Ultra gaming in 720p?

Ok, Build day, my last package arrived an hour ago. Everything is here, except for one thing... a monitor...

But I have this 720p TV. So I'm wondering if anything will go wrong. I know I should be able to just plug it in and use it like a monitor, but from my past experience, it has a weird aspect ratio, had to adjust it with an old PC. What I want to know is, if I game on this TV in Ultra settings in 30fps (it has a low refresh rate), and then switch to a 1080p screen with a 144 refresh later, will it hurt anything? I am paranoid about it... it should be fine right? I am so paranoid, but I've been waiting almost 3 years saving for this PC, 3 tax returns later and now i don't wanna wait another 6 months to a year so I am tempted to use my TV I use with my console. Sorry for all the dumb questions forum, this is my first ascension and I just want to avoid any mess ups possible. 

My PC specs are:

ASRock Fatal1ty B85 Killer LGA 1150

Intel core i5-4460LGA with Stock heat sync

Corsair Vengance Blue 8GB

1TB WD Blue HDD

Corsair CX750m PSU

ASUS GTX 980 STRIX DC2OC 4Gb

Nzxt Case S340 with two stock fans and two front fans. 

Windows 8.1

Wii controllers and sensor bar :P

Aspect ratios and input lag may be a problem but those are inherent to the TV not your computer. this is due to older/lower spec hardware on the TV and hdmi limitations.

The only thing that will hurt is your eyes. They will be in utter awe once they are shown the light of gaming at 1080p+ 60hz+   Join us brother!

Look forward to your monitor upgrade. That system deserves better than a TV.

Guess I'll be playing AC:Unity until I get a monitor, seeing how it seems to run in 30fps :P