Htaccess help.

[wetlo]

I hate to ask that question becouse it was asked many times, but I still can't find satisfactionary and working for me. Ok here it is want I need:

1. Redirect from non-www to www
2. All files have php extension. I need to hide it.
3. Index.php redirect to root domain.
4. I need inner page to appear with slash. I mean www.domain.com/post redirect to www.domain.com/post/
5. Redirect www.domain.com/post.php/ to www.domain.com/post/

Hope everything is clear and you can help me. Sorry for my English.