Go to settings and go to system settings then look for flash player then press it . But you need internet.
How To Put Adobe Flash Player On PSP?
No you can't but if you want youtube then a good place to get them is "WWW.pspicy.com". Just follow the links to free videos, music and much more. By the isn't an advert, I just think its really good :) Liam from St. Helens