The case doesn't matter. You could use no case if you wanted. It's the "PSU" you are using that's the problem. 450W is more than enough for your system, but as I said above you don't have a 450W PSU. I'm not trying to be a jerk and make you feel bad about the parts you have. You keep talking to me however like you completely don't understand the point I'm trying to make. I never said your case was low end, I said your PSU is. There are many 450W PSUs I'd trust with your system, that's not one of them. And you'd do yourself a big favor by not lying to yourself and saying it will be fine.
Edit: Lets look at a hunk of junk.
http://www.newegg.com/Product/Product.aspx?Item=N82E16817148051
Here is a "450W" PSU. If you look at the specs you can see that although it claims to be a 450W PSU, it lacks any kind of PCIe plug. My 450W PSU has two 6+2pin PCIe plugs. This doesn't even have a single 6pin? If you try to look up the power info it's completely lacking. The chart with the power distribution only lists what the single rails are limited to. You can't just add the two 14A rails together to get the total 12V rail output. Even if you did you only get 336W, nothing near the claimed 450W. 14A is also REALLY low. Most rails are limited to 18or 20A. While the 1050TI isn't a high draw card, the rails on this PSU might still have issues powering one if they are limited to 14A.
I can't find any reviews or anything on your "450W" PSU. But I suspect it's of a similar quality to this unit. Try using it if you want, but don't kid yourself by calling it a 450W PSU.