OK so if it was my truck. I would first check the compressor to see if it rotates by hand? If it rotates without binding you maybe OK. You may have to put a wrench on it to rotate it, make sure you are turning it in the correct direction.
If it is seized on the inside then I would definitely pull it off. I would then check the refrigerant ports for debris. If there is no debris you might be lucky and not have garbage in the system. You may be able to just replace the compressor....you need to be careful on getting right oil amount in the system. Did you add extra when you replaced all of the components?
There are a couple of things that come to mind with the pressure relief valve opening, too much oil or blocked condenser. But the condenser is new and everything was working OK before.
I have seen on a machine where the oil amount was too high, so much so that the compressor was trying to compress oil. It makes a hell of noise, it can cause the compressor to vent out the relief valve and it will bend stuff on the inside of the compressor.
If you can turn over the compressor and there is no debris, it may be worth a try to recover the system, pull a good vacuum and recharge the system. The pressure relief valve will re-seat or at least the ones we use do. I wouldn't add any oil back in as you may have too much.
I honestly do not have any experience with aftermarket stuff we usually use Sanden's or TCCI.
If you do find debris in the compressor ports. That's a crap deal and I usually replace everything. You can flush the lines, but I have seen where valve debris has actually embedded in the hose inner liner, which caused a leak down the road. The aluminum evaps and condenser they use now days you can't flush them out. And they will plug if you have too much oil in the system.
Wish I was a little closer to give you a hand.
