Playing 4 tables of full ring TAG-style, I only see about 15% of flips, 20% at most. Although this sounds ridicously tight, it's not like I have a friggin' "robot" hand range. I'm quite capable of using game theory to bluff with a marginal hand (like suited connectors) in EP about 10% of the time.

I would still suggest at LEAST 20 full buy-ins. Even with conservative play, you could find yourself in a streak where all your cbets are getting reraised and/or you never hit a flop.