Deku would be pretty cool actually, he has speed and lightness on his side... plus the far greater potential for getting back to the stage. But he'd be weak.
Goron would be a lumbering Sonic with tough fists but a poor ability to get back to the stage.
And Zora would be a middle of the road type with an average speed and jump and attack.
Ya I'd imagine deku link to feel a bit like ivysaur (his speed and weight) and his moves:
Up b (on ground) - burrow untill you let go of b (or until a timer runs out so people cant just hide in the ground). When you let go of b you shoot out into the air and then can float with the flower petals
Up b (in air) - shoot up and then float with the flower petals
side B - deku nuts - shoot a deku nut and stun oponents. if you're in the air you drop the deku nut and if floating with the up B move, you can throw the deku nut without interrupting the float. The deku nut would hurt you on contact, and would work like ivysaurs spores if they land on the ground (you get stunned if you're near the deku nut when it lands on the ground.
B - bubble charge. this move could perhaps work a bit differently than in MM. If its charged a tiny bit and hits someone it does a bit of damage. But if fully charged, it can trap people inside (like in bubble bobble for those who know what that is).This gives you an opportunity to attack the person in the bubble. But also, the bubble would pop at some point. When it pops it does more damage/has more knockback. So if slightly charged it does a bit more damage and knocks back a bit when it pops, but when fully charged and it pops it can almost be like a kill move if someone is highly damaged.
Goron link id say would be a combination of sonic and donkey kong.
Up b - i forgot what its called, but he would roll into a ball and jump into the air and then come down and smash the ground
Side B - kinda can work like sonics OLD side b, but instead of charging the spin on the spot he would start rolling forward slowly, and would be able to deal small amounts of damage. if you roll long enough the spikes appear and he rolls faster and does more damage. at this point it would work much like sonics side b did, except you cant jump off the ground, and turning would take a lot more time.
B - punching combo. this would kind of work like the sword dance, but it would be much more powerful and much slower.
Zora link i think should feel a lot like lucario/fox/shiek - most of his A attacks should make him feel very much like a ninja.
Up b would work similairly to lucarios up b except he would have that forcefield thing around him when he does it.
side b - he would throw both his fins and they would work like links boomerang, but there would be 2 of them to have to watch for
b - he would use his force field as a reflector/it can deal damage and enemies can get stuck in it similar to lucas' down b
