SamyGO

I pay monthly fee for eurosportplayer.com (Bundesliga footbal, etc.). Eurosportplayer forces to use Silverlight on IE, Safari and Opera, but uses HTML5 on Chrome, while the latter HTML5 plays much smoother than Silverfast on my PC. But I cannot start eurosportplayer directly on Smart TV JU7000 Tizen web browser. Any idea with how-to, any help with settings?

You should better bother Eurosport to develop Player widget for smart TV imho
And ask them at the same time why it doesn't at least work in browser. I'd say matter of DRM or so, surely nothing that you can "setup" yourself...

It looks eurosportplayer.com requires Flash.
How we can install Flash to the 2015 Tizen web browser?

You can't, and it's using HTML5 anyway