I have no idea why its not available too. Guess we will never know the answer.

Yep, bt = bittorrent. I usually use these words together here, so most ppl understand it.

There are these steam download browser plugin. But I have never try any. Neither do I know if they actually work or not. So I can't recommend any.

Regarding Flash, there is always the possibility of downloading an older version of browser to use/play it.