I haven't experimented with toe-in up front, so I can't comment on that.
Keeping the stock camber settings is fine. Additional caster will reduce the amount of dynamic camber gain, slightly, and will improve the on-center feel of the steering. Personally I think leaving camber on the table up front is pointless... you can't get too much negative camber with the stock setup, especially at stock height. However, if you are never pushing it to the point of understeer, then you really don't need to improve front-end grip.
I would go for as much additional caster as possible while keeping it within reason between the two sides. Again, I don't think you can get too much caster with the bushing kit alone and more is definitely better unless you want super light (read: vague) steering.
OEM & Aftermarket Parts