I would think this must be a rec.bicycles FAQ but I couldn’t find it.
When you say “killing you”, are we talking about bruising, or chafing? I have found that all bike shorts seem to fit me differently, and I’m guessing that what works for me won’t work for others and vice versa. One constant has been that more expensive bike shorts do tend to fit more closely and chafe less.
Baby powder gets wet and lumps up, as does cornstarch, probably not much help.
For a long ride, I try to wash very well with soap and water shortly before the ride and use a bit of antibiotic cream in a couple of spots where I tend to get chafe. The bugs that live on your skin will get into a chafed spot or a wounded hair follicle and hey presto you’ll have a saddle sore. Not fun.
I’ve never really used the creams and ointments and such, and would use any kind of grease sparingly, as I think it would get into the chamois and prevent it from doing what it is supposed to do, which is absorb sweat and keep your skin relatively dry and intact.
As for saddles, they’re a very personal thing, but finding one that supports your sit bones properly is crucial. Extra padding seems nice at first, but once you have some muscle in your bum you’ll find that it actually causes more problems than it solves. For a traditional road bike, a firm, narrow saddle and good bike shorts tends to work out better than a wide, soft saddle. I don’t have much experience with riding hybrids for any real distance but I would guess that you probably wind up sitting _on_ the saddle more than you do on a road bike.