R/C Paperboy:
1) yeah I think you can still get the steel outdrives, if not get yourself some IRS lite drives, or pretty much any other aftermarket one. You could also try Square's delrin ones for less rotating mass
2) never heard of anyone doing this... but there are some aluminium hubs out there if you want to try them... or a lot of people use losi rear hubs for extra tuning options, but I don't think they're any more durable
3) Yep, there's a new HD oneway out now. Less breakages due to 6mm oneway bearings. part no is 3978