Some users have recently had their accounts hijacked. It seems that the now defunct EVGA forums might have compromised your password there and seems many are using the same PW here. We would suggest you UPDATE YOUR PASSWORD and TURN ON 2FA for your account here to further secure it. None of the compromised accounts had 2FA turned on.
Once you have enabled 2FA, your account will be updated soon to show a badge, letting other members know that you use 2FA to protect your account. This should be beneficial for everyone that uses FSFT.
If it can actually do what it says it can, it'll work fine.
The difficulty is, many PSUs can't. Some "600w" units explode at 300w.
Hence, we need to know the make/model.
That sounds more like a speaker than anything else.
If it IS the PSU, replace that thing now.
What model Tt 750w PSU is it, and how old is it?
I ask because the Tt TR2 series, excluding the 80+ Bronze units, is know for being Meh at best.
I seriously doubt it'd pay for itself.
Unless the CPU is at full load constantly it's likely idling along at 10w or less, you aren't going to drop that much on a new platform.
It stops well short of the slot: http://pro-clockers.com/images/review/thermaltake/nic%20f4/f4_30.JPG
Plenty of room, even for GPUs that have a backplate.
Now if it's a passive GPU that has a full on heatsink strapped to the rear, that might be an issue.