About Carnage, that was also Zeb Wells' canon for that symbiote when he did the two miniseries depicting Carnage's return, that basically the symbiote was like a child raised by a psychopath, with the natural implication being that if it had bonded with someone of stronger moral fiber, it would have turned out halfway decent. Also, I remember the MC2 example and that was my favorite handling of the Venom symbiote, that "she," as Mayday called it when they were bonded, had been redeemed by the one host that showed it compassion and love instead of rejecting it out of fear (Peter) or twisting it into a murder weapon (Brock), enough to sacrifice itself protecting Mayday from Hobgoblin.
Also, I do get the logic behind Peter's distrust of April, but at the same time it's him taking his issues out on an relatively innocent person who was just as much a victim of Osborn as he and Gwen and Mary Jane and anyone else Osborn hurt. It's something that just sticks in my craw, partly because I'm not a big fan of people getting mistreated for other people's crimes and partly because I feel Peter himself ought to know better from his own history of being unfairly demonized because of his perceived associations or whatnot.