Granted I'm not playing on PC but I've never had any of those issues either. Now, I've seen Watchmen find their sleeping compatriots and wake them up, but I've never seen any evidence of random respawning before, and my strategy most of the time is to clear whatever building I'm in, stack all the unconscious bodies in a closet somewhere, and then go about my business exploring/searching for loot. Never had anyone come back unless they were found and awakened by a buddy (and you can normally hear that if you're within earshot "What are you doing? Get up!" or something to that effect).