1. No, not really - try leaning forwards a bit more
The harness can take a bit of playing around with, it sounds like you might have over-long shoulder straps.
2. Crotch strap is usually vital on a wing, as it'll ride up to your armpits without them. The shoulder strap is useless - it's a carry-over from people who think a rucksac is a good example of a well-designed harness. IMHO, anyway
3. As Gavin says, stiffer webbing is what you need. Mine is wonderfully rigid, but my dive shop doesn't sell it any more, and I've never found another supplier - I'll have to give Beaver a go...
4. I use the plastic c-shaped clip supplied by AP Valves, slid onto the webbing. Most people use bungee tho.
5. If you haven't got anything you want to clip onto it, take it off. I still find it hard to believe there are people who clip things onto their crotch straps