i have a well upgraded 10mm pistol and combat rifle for my no kill stealth run and ive maxed out the following augs: hacking stealth, lvl5, icarus landing, high jump, punch walls, lift heavy.. so i have been able to have access to pretty much the whole map by early hengsha. havent touched any of the armor or combat upgrades.

i have a pretty broken way of dealing with multiple baddies... just shoot a silenced 10mm round near one of the baddies and keep doing so while luring him away from the group, then do a takedown when hes alone... rinse and repeat. no need for the reflex booster

also, i have a tendency to explore the whole city hub before i start on the main quest. but i might have to stop doing that because i find that alot of areas are closed off (ie the door is not even openable) until you trigger a main story quest and you do alot of backtracking to find the sidequests