I am building a pc soon and have a TV. Should I use the HDMI for it? Should I run all my games in 720p?
Definitely can do it, it will do just fine.
Small text might look kinda poopy, but that's it. I use my 42" POS Flat screen's internet explorer feature on Xbox sometimes and I always have the hardest time making words out. But yours is nicer and smaller so it should be fine, I'd just try to switch to a monitor whenever possible.
The Xbox's browser sucks but the text look about the same on my current all-in-on-pc.