When table selecting I start with all the things you mention, big pots or lots of players seeing the flop but obv both is ideal. When I've played a couple rounds at a table you can usually tell if there's reasons to stay. Once I'm at a table I never look at the table VPIP any more because all the info I need is at the table and that makes my decisions. Before sitting I tend to avoid joining if there's a shorty to my right as even having position on a decent player with a full stack is more +EV but I'd leave that table too lol.
If there's a giant fish at the table I'm staying no matter where he is. Obv move around the table to get better positions when I can. If everyone's decent or even if there's like a 70/3 across the table from me I usually leave because we're not going to get tons of money off him as it will be difficult to isolate him too and there's always better tables to find at 2/5/10nl.
A paraphrased section from Veneers guide to uNL 2010. We should always have a reason for being at the table, we want a MASSIVE edge at the micros and there will always be decent tables to find if you look, don't settle for anything less.
The difference between mid-stakes players and micro to small-stakes players is the shark mentality that they're there to make as much money as possible, when a table is running at higher stakes it's for a reason and when those reasons aren't there any more a table will quickly break. Take that mentality to micro-stakes, look for a massive edge and take maney.