1). Here's my profile:
http://us.battle.net/d3/en/profile/nicoga3000-1757/hero/14921167
I have only ~400k gold, so I don't have much. What should I be working towards gear wise?
Critical Chance, Increased Attack Speed, Critical Hit Damage
CC, IAS, CHD
This is what's referred to singularly as "trifecta" when people talk about a single gear piece.
Build up enough defense so that you don't get one-hit killed by whatever enemies you intend to regularly face. D3 purely rewards offense over defense now.
2). Should I aim to clear MP0 and then start farming MP1 for gear? Or should I just jump on MP1 ASAP?
Act 3 and Act 4 is fine for MP0. Acts 1 and 2 require MP1 to ensure L63 drops.
The first goal is comfortably running A3M0. Nobody farms A4 because the layout sucks. Once you've build up enough, run A1 or A2 for diversity.
Run with groups if you want to do key warden hunts or uber runs. Higher MP the better there, and much less efficient to do so solo regardless.
3). Is there a good list of stats to watch for on drops? I've literally been selling any ilvl 62 or less, and stashing 63 just in case. No clue what I'm looking for though.
That's a mistake.
Item affix values roll on the basis of the monster's level from which they're dropped as opposed to the item's level.
Pay attention to the affix values and pay no attention to the item's level.
IAS is still basically king.
CC.
CHD.
Weapons - Sockets. Life leech (X% of damage is gained as life). IAS. CHD. Primaries (STR DEX INT).
Jewelry - Trifectas. Minimum and Maximum Damage. LOH maybe. AR, primaries, vit on the lower end.
Other - Triple digit primary. AR. Vit. Dual resist (AR plus single element resist) might help.
Shields - Worthless.
An easier way to price items you find -
Right click on the item while in the auction house, to "Search for similar items". X out all but 3 which matter. Search and sort by cheapest, and assume that your item won't sell for more than 50% less than what's cheapest. The above stated affixes usually matter. Affixes which don't matter -
Thorns, globes, crowd control, status ailment on hit (freeze on hit, stun on hit, &c.), life regeneration, life on kill, % damage reduction from melee/ranged, % life (doesn't command a premium), arguably magic find (I consider it snake oil), +armor (important but nobody prices for it).
4). And I have to ask - are ponies even worth doing?
No. The map layout sucks and enemy placement is sparse. Nobody does it.