1. You don't need a UV filter. See Fishmeister's answer. Get a good Circular Polarizer instead - they are truly useful.
2. I think what Canon charges for a lens hood, or that they charge at all for one, is outrageous. However, they are a good default choice and you won't have to worry about vignetting.
3. Art supply companies, hardware stores, your linen closet, dumpsters at construction sites, a piece of something plus a can of white spray paint (makes a lot of them and you can make silver, gold and many other special purpose bounces. I once used a customer at a crafts fair booth as a bounce. He was wearing a white T-Shirt and that was all I needed to just lighten up the shadows a bit. Bounces just bounce light and anything that you can get where you need it and bounces light is as good as anything else. Maybe not as convenient, but as good. Any pro camera store or site will be happy to sell you bounces and there are reasons to buy them, mostly convenience.
Foam core makes a cheap bounce and you can make bookends out of them in the 4'x8' size. Another option are the foam insulating boards used in construction. You can get a silver bounce and a white bounce out of them by stripping one side of it's covering.
A white sheet and clothes pins, 'A' clamps, duct tape, yada, yada, is very useful. A variation on the sheet is a white shower curtain.
A silver reflector that is compact, transportable, cheap and useful for portraits are the sun reflectors that fit in car windows.
Anyway, I'm sure you get the idea.
Vance