With my first BMX bike in the mail, I am trying to figure out what protective gear besides a helmet and gloves I should get for street/park riding and would welcome advice. The facts: I am 26, a chick, and new to BMX, but not falling. I have two mostly healed injuries from other activities: ankle and elbow, but probably only the elbow needs to be babied a while longer.

What do you use when you are trying something new? What needs to be guarded the most?
Aren't hard shell guards pretty inflexible and therefore annoying? I tried some knee pads on and hated them.
What offers the best protection with the least intrusiveness? Brands?

Thanks.