it would be easier and saves memory locally and you can have replays play on the steam workshop if you put tb on the steam workshop when its released.

This would imply toribash can run on a webpage.
HINT: It can't.

Yes I have tried and missed for that more then once
Anyway just use the replays tab at the top
Easy peasy

when you watch the repay you move camera to see fight from different points. to do same in web-browser will lag hard.

Replays could be handled by the Steam Workshop without having to have any web players etc opening the possibility for some form of "replay cloud".

Web playback... Been addressed before.