Great post by the way!
I think I went through pretty much every stage you mentioned (raising A2o in any position, calling raises with bad cards, etc). It is truly amazing how much playing these games will impact your overall game. I've played about 6k hands so far and I would say without a doubt it has improved my hand reading, reading opponents, position play, heads up play and how to play short handed pots. Also when the full ring games start to get shorthanded you will almost always clean up - your opponents are often clueless as to what changes to make. You will learn how to stop playing your cards for what they are and to start playing against your opponents. And your full ring game will benefit as well. A few tips if you are just starting out:
1.) Take note of the kind of game you are in. 6-max games vary greatly from one to the next. In some everyone limps and you can limp along with many hands you'd otherwise fold (these become very much like full ring). In some you can steal the blinds every time you are on the button or CO. It is far more important than it is in full ring to figure out what kinds of players you are against. When I first started I played every hand the same and was trying to bluff out calling stations with ace high. They'd show their bottom pair and drag pot after pot.
2.) Along the same lines, I would recommend reducing the number of tables you are playing. I started off trying to play 3 at a time and this was too much for me. 2 is about right because I feel I can get good reads on all 10 (max) of my opponents.
3.) Try not to limp unless someone limps in front of you (the exception being hands like pocket pairs in a passive game). You are basically announcing that you have a weak hand. Raising can often buy you the pot (either right then or with a flop bet when everyone misses). Also when a weak player limps in front of you raising will often get it heads up and giving you position.
4.) Don't play too tight. If you try to play exactly the same as you play in a ring game you will be a marginal winner at best (unless you are a loose ring game player!). Hands like JTs are strong in 6-max.
5.) Throw away the low suited connectors unless it's going to be an unraised family pot (obviously it's ok in the blinds if you're getting good odds). Heads up you are already starting with a pretty big disadvantage (best advice I heard of was from one of sthief09's articles - think of 76 suited as 7 high and see how much you like it!).
6.) Pairs and aces go up in value. AK is often good enough to see the river unimproved (since if your opponent doesn't pair you win).
7.) As was already mentioned, don't get crazy aggressive. J4o is still junk, A2o is typically not worth raising unless you are opening from the button. VP$IP is usually around 20-30%.
8.) When only 2 of you see the flop don't always assume you are way behind if you miss. There's a good chance your opponent missed as well.
9.) If there are fewer than 6 players, pretend the first couple have folded.
A few more articles:
Jason Pohl is frequently mentioned in the heads up/shorthanded forum and his articles are here:
http://www.pokerpages.com/articles/a...index.htm#pohl
And some good shorthanded (and full ring) 2+2 archive articles listed here:
http://www.poker.favos.nl/