Warring this is long story but do have questions need answers for go to bottom for real question need answer if don't want to read a story

Kind of said it all, did searches but none covered these. To tell story of this 2000 CRV LX AWD was last owner blew head gasket and just keep driving till blew it up and then let it sit with water (not coolant) in motor for 2 yrs till it rusted the pistons and all coolant systems and motor was locked up when I bought it. So no saving old motor so do what I do get a good JDM B20B and do the swaps and wire splice on ecu for no crank sensor done on many CRVs no problems. Bought 2 CRVs at time had to put motor in both but when time got to this 2000 crv coved -19 had hit hard and took 4 months to find motor (at not a crazy price) cause the importing was messed up but that's for another story other than had to get one with high intake (was high compression thou) not the low intake so swap out from old motor.

So now car runs and time to look at the a/c compressor was spinning but didn't seem like there was anything going on with piston but did vacuum and would not hold so said replace compressor. Install and also new dryer and all gaskets with green - vacuum and all good so move on charge and compressor kicks on right way do the oz and seems good, but can't really test because the blower will not start so thinking good the compressor kicked on so once fix blower (that all be for another story) be all good.

Well no cold air, all fans kick on compressor kicks and hiss from under clove box but no cold air out vents. Compressor seems to kick off faster than normal and pressor is in red till compressor kicks on, guessing condenser is blocked? Where should go from here.

Last doing shake down runs got a CEL was for knock sensor , and could hear pinning when was on it hard. Had half tank of old gas so don't think it's that, but other than check timing (using distributor and wires from old motor cause were all new) maybe put the one from JDM back on. Never heard pinning from the B2B motors (unless rods knocking) didn't even know they had sensor.
Any help thanks