raginggoblin

Looks good so far.
Notes:
Wear//Tear doesn't need to be mainboard.
Punishing fire isn't modern legal, if you're going for modern.
Some token making cards like raise the alarm could be pretty good
Intangible Virtue is almost a must here.

Here are two different merfolk lists I've used in the past, try looking at them to get some more ideas about how merfolk work. You are trying to do too much here, merfolk are a very simple and hyper aggressive. You need to make sure you have the correct merfolk to be able to beat down and win (4 ofs of master of the pearl trident, lord of atlantis, and merrow reeejery are ALL a MUST).

Mono blue:
http://www.mtgvault.com/raginggoblin/decks/merfolk-2/

UW:
http://www.mtgvault.com/raginggoblin/decks/uw-merfolk/

Try replacing intuition with show and tell. Your careful study and entomb are enough to get fatties in the yard. Show and tell offers and alternate way to get your guys out in case of stuff like deathrite shaman hating out your graveyard.

Very nice. Not necessarily legacy competitive, but very silly and totally capable of an explosive turn 2 win. Try adding apostle's blessing. The white is phyrexian so you can cast it in your colors, and it can give you some much needed protection from removal like abrupt decay and swords to plowshares.

I love this archetype, and it's interesting that you decided to cut black.
I do have a little problem with your land base.. 17 just feels too risky. Since you have experience with the deck if you feel that number is appropriate that's fine, but Tron is another major archetype you should be prepared for, and once karn hits the table and starts exiling your lands, you really can't come back. Also, the low land count means that bloodghast and hedron crab's landfall will be difficult to consistently trigger. So much so that i'd say just cut bloodghast.
Also, as long as you're running blue Gifts Ungiven is pretty solid.

Lastly, are you local to Detroit area or will you be travelling? We've got several nice card shops to test modern at in the Utica area, and if you're near there check out Gamer's Gauntlet.

You're a little light on instants/sorceries for your delver. I also feel like goblin guide is a little out of place here. If you are trying to play a tempo game, I'd cut the goblin for more control cards.

If you are using isochron scepter, you really shouldnt pass up on running a few copies of silence and research//development. One of those on a stick can totally take over a game.

Unfortnunately (while a cool idea) this deck really isn't modern viable. The idea of using pongify and hybridization on 0 cost creatures seems mana effective, but you will have a big problem keeping your hand full enough to consistently make creatures. Sure, you may get one or two early turn 3/3's, but this isn't legacy. That strategy won't work without the correct spells to back up the tempo plan. And if you are looking for all out aggro, gruul and naya do it MUCH better without worrying about emptying their entire hand just to meet an abrupt decay and a path.

I don't mean to be a downer, but this is a casual deck. Removal in modern is too good for a couple 3/3's to beat in for a kill.
Cute idea though..

I like the concept. A lot of good synergy here and some good power cards.
A couple suggestions though:
not a huge fan of essence scatter / hindering light, I'd say cut them for some mana leaks or remands.
a full playset isn't necessary, but it'd be worth it to have a few silences for the isochron scepter.

Overall looks good, hope it does well!

I'd say take out the tusker for mauler. Being RG instead of GG makes it easier to cast.

Also, youll have to do some testing and figure out what works, but you REALLY need to find room for goblin guide. a 2/2 haste for R is a dream come true for this deck.

Goblin guide is a must. And don't use elvish mystic. Your creatures need to focus on attacking, not producing mana.

Second, you seem a little spread out here. You should try to cut one or two of the 3 of's and round off playsets. A lot of decks benefit from having 3's, but in a fast aggro deck like this you want your draws to be as consistent as possible so playsets really are necessary.

Also, consider cutting kalonian tusker for scab-clan mauler, you need to trigger bloodthirst but since you arent running a full playset of shocks or fetches you will probably have trouble having GG on 2. Especially since you want to make sure you have red turn 1 for goblin guide and vexing devil.

I like the inclusion of madcap skills. very solid aggro card

You can only activate the ability by paying it's cost: tapping the creature. So unfortunately they would still only tap for 1 each. The reason I also suggest gemhide as well is you want to ensure that you have a mana producing sliver every single game, and sometimes extra ones in case of removal.

You should look into the older slivers, there are a lot of good ones that are also modern legal.

Because slivers curve out so high, I'd recommend adding gemhide sliver in addition to manaweft sliver.

Don't use ratchet bomb, it has too much potential to hurt your creatures too.

I like descendants path in here, as long as your creature count is so high i'd recommend adding a third too.

It is expensive, but i REALLY recommend improving your land base. ravnica shocks and zendikar fetches are almost essential.

Slivers, much like allies, rely on having a board presence to be stong, and if your opponent is able to deal with them one at a time they can't win. Something like Asceticism could help protect you from removal.

This still has a ways to go before it could be modern playable, but keep researching cards and trying new stuff and it can do pretty well.

That's good in theory, but it's too easy to make fake accounts to upvote their own comments.

triggered abilities that add mana are also mana abilities. You may have just been confused by terminology there.

I think you're concept of the stack is a little skewed. While, yes, you can activate mutavault in response to he path's trigger, the fact that it uses mana to activate it is irrelevant. I believe you made a comment on a deck previously talking about mana abilities, and I don't think you fully understand what they are. Abilities are activated at instant speed unless otherwise specified (ex level up). A mana ability isn't unique in that it can be used at instant speed, but rather that it itself can't be responded to.
** Only abilities that ADD MANA to your pool are considered mana abilities. **
Additionally, you can naturalize an enchantment in response to it's ability, BUT the ability WILL STILL GO ON THE STACK and can therefore still resolve.

ps: im not yelling theres just no italics and I want to stress certain words.

I personally prefer to make my own decks to. The problem that you run into though is that sometimes some archetypes actually don't have enough good cards to make them good enough to compete.

As for making budget decks, I totally understand finding substitutes for cards (I can rant pretty long about the secondary market prices of magic cards) but in that case please specify that the decks are budget so people know not to suggest the better cards.

Lastly, I have a friend who doesn't like making decks, he openly admits he's bad at it and he's the only one in my friend group that net-decks. But to be honest, there isn't anything wrong with that, some people get their enjoyment simply from playing the game, not necessarily the deck-building part.

It's not a matter of individual cards, it's overall deck composition. Personally, I am a Johnny, I love making new decks with combos people have never used before. Unfortunately, these aren't always 'good', and is important to understand that no matter how fun the deck, it has to have some degree of competitiveness to it or it will only lose. In the end, magic is played against an opponent and unless it's opposite day, you are supposed to try and win.

... The irony. oh. my. GOD. the irony...

I feel like I'm starting to get redundant, but with so many comments like "save competitive for tournaments" I really feel like I need to say something:

Being competitive is all about attitude, the WAY you play, it has nothing to do with the deck you use. However, when people INSIST on using stacks of trash for decks, that's not being casual, that's being dumb.

Once again, I'm sorry that it may hurt your feelings, but magic is a game that requires skill and intelligence even at the least competitive levels. Learn to play it the right way.

It's good in draft. Outside of that it's pretty much trash. Sorry.