There is no place on an AR15, other than when used for assembly, for grease. In fact, if you're going to be running more than 100 rounds between cleanings, using grease is likely accelerating wear. Lower viscosity lube works best in an AR because it flows and the cycling of the action allows the lube to displace crud as it builds up. Grease keeps the crud where it is and essentially becomes lapping compound as it mixes with hard particulates.
There is nothing complicated about lubing an AR and it doesn't take some special concoction that you have to mix at home to get it done. Find yourself a reputable synthetic lube, like Slip 2000. A drop or two on the charging handle, a drop or 3 on each of the rails of the bolt carrier, a drop on the cam pin shaft, a drop for the extractor and ejector and a couple drops in the vent holes for the rings. Wet the bolt lugs and you're done.
If your setup was running and stopped running when you added the suppressor, it's probably because you're way over gassed. What you're describing sounds like very excessive bolt carrier velocity. Instead of tearing your hair out with with buffers and springs, why don't you just install an adjustable gas block. Turn down the gas to increase the closed bolt lock time. This will result in less bolt velocity.
Either turn the gas down or go with a low back pressure can.