you shouldnt be worrying about lean angle on the streets!!! you never know what lies ahead of you in a turn, sand, rocks, leaves, another car, ect.
if you really want to test your limits take it a track.

tire: a 180 tire is plenty. its hard to explain on the internet, but a racer's chicken strip is different tha a street rider's. street riders look at how much tire is (is not) scuffed, where a racer looks to see where you is actually rolling on the throttle while lean'd over (someone else decribed it as looking like an eraser).

alot of sv riders still use a 160 rear tire at the track and dont have any problems

body position: (not directly adressing you casue I have never ridden with ya) you need to learn body position, you will start to see that you are actually pushing the bike more upright to keep a larger contact patch while at full lean. once you learn body position you can use your knee as a gauge of how far over you really are