Control Windows From Mac

[kicks66]

Ive got a fast pc at home but a very poor CRT that it is attached to. Id like to use the screen of my Macbook instead to play games on, so is there any way I can stream the PCs screen onto my Mac and have control as well?

 

[kicks66]

Whilst the above should all work I would not like to play games using this method.

How come? Is it to do with the lag? Im planning on mainly playing strategy games, and it will only be over home network ethernet.