As for stop-and-go riding, you can definitely do it. I became most familiar with my clipless pedals by riding in stop-and-go traffic. Ride for 30 seconds, unclip, wait, clip in, ride again, etc. It becomes an automatic motion.
oh yeah, i forgot about this... yeah, i agree. i can get in/out of clipless faster than clips/cages/straps any day. i personally *hate* unclipping so i practice doing track-stands at lights or grab a pole, but this is unnecessary i just do it for *fun*
after a few weeks the twist motion to disengage is habitual and you won't have any problems. learning to quickly engage takes a little more time, but this too becomes a "no-brainer" with time -- 90% of the time i clip in with the first stroke...
for any distance more than a mile or so i definitely use either clipless or cages/clips/straps for the performance benefit (i am also so used to them i destroy my shins by accidentally "spinning" the pedals if i ride flat pedals)