There are lots of bad ones, especially if you play with some higher stakes. Playit (since it's on the list in this thread) is one of them. They are owned by the more famous betandwin that is known for killing limits with even a win or two. Stay away! I'd stay away from smaller bookies as a general rule.
My advice would also be to look for bookmakers that are regulated by someone. If there are some disputes you need to be able to complain to someone. For instance, Centrebet is monitored by the Northern Territory Gaming Commision and will help you if there are any problems.
Go to
http://www.bettingadvice.com/showBookmakers.php .. real reviews made by hounest guys..
the q's:
1. internet1x2.com will work fine for you. Stick with bookies like that and you won't have problems. In my opinion, most of the guys that has problems betting online is from the us and is betting with some shitty small two-man company offshore.
2. they won't close you down, but they will kill your limits for sure. Depend if you're a high roller or not though. $10-1000 stakes are generally no problem, but $10000+ can be. Some companies like pinnacle actually posts their limits.
3. I have my money at Centrebet and Pinnacle. High limits and high odds for those markets I'm in. Plenty of other good ones but depends on what you need. Those two isn't any good for special bets punters for instance.
4. tons of good boards around, but what sports do you like to bet on?
... ps, if you don't want to deal with limits etc, go to
www.betfair.com (it's not a bookie but a betting exchange) and open an account. You can bet or lay any team and they only earn money by taking %'s of the winner.