I play on PS3 and seem to play against only three different teams.

Montreal Canadiens (Most often, 80% of my games)

Pittsburgh Penguins

Los Angeles Kings

Is it similar on Xbox? I'd love to see people using other teams out there, but I never do. 

L1+Select button on PS3. Similar Key binding on Xbox

Not all of the characters are built for FFA. Simple as that. Jak is a 2v2 built one. I'd say that Sackboy, Parappa, and in some ways even Nathan Drake and Radec fall into that group. They are characters that excel at pestering from a "safe" area while their teammate acts as an overly aggressive decoy. I've seen several teams use this formula, and before 45 seconds have passed, the one playing it safe from the corner is at a level 2 super. 

All in all, you can't expect every single character will be on equal footing when it comes to a fighting game. There has to be some character bringing up the end of the roster. In my tier list, I unfortunately have Jak listed at dead last, it is to bad that he is your favorite, and didn't turn out the way you had hoped. I was looking forward to playing Nathan Drake exclusively before I picked it up, and was quite disappointed when his moves were overshadowed by Kratos, the Coles, Raiden, and Dante. Good Luck!

I meant I play Heihachi, not Ratchet. My brain is still on first few hours of gameplay.

To answer your questions that you asked..

1. Yes, the shield does have an affect, it doubles the amount of AP you generate from attacks. I was wondering that myself and decided to try all of his different attacks with the shield and without. For instance, the bone/axe throw move that he throws in a horizontal line generates 10 AP without the shield equipped. With the shield, it generates 20 AP. 

2. Most people that I see that are good with Sir Dan use a combination of Fire Breath, axe/bone throw, and his charge move all with the shield equipped. He also seems to be a favorite of a few people that have mastered him online, and is incredibly difficult to play against when he is played right. He has a higher than average melee range.

3. (Off-topic) Toro is a great character, and one of the best of the "small" ones to choose from. His curtain moves are where he shines, you can change your playstyle mid-fight easily. I use Toro, Ratchet, and most recently Sweet Tooth the most.

Interesting things you have come across. I can say that none of those things you stated have happened to me in the 20 hours I have played the game. Though, at times it seems to take far too long to find a match online, Ranked or Unranked doesn't seem to affect this.

Completed. 

Working on getting the trophy that requires you to invite a friend to play an online match. Alas, none of my friends currently own PSASBR. Anyone out there lend me a hand?

I'm working on Portal 2, can't complete any of the co-op ones because my roommate gets nauseous when she tries to play.