1. With the firefox add-on flashblock will block flash videos until you click on them. You can also Whitelist sites so the flashes will load there if you want. I would also recommend upgrading firefox to 3.6.3, for increased security and stability.
2. I'm not quite sure what you're asking for your second question. You may ask it in your native language if that is easier. I may or may not be able to translate it.
3. The Windows one on this page should work with xp: