@chinyoti - others are correct in saying that you shouldn't keep on changing parts just because someone said so. Find the cause behind the erratic behaviour. I also suspect the usual ills (incorrect charge, atmospheric contamination etc leading to further problems).
@HellsGuardian - like afnan said, listening to the sound amplified can confirm if its coming from within the compressor; you can use a long screwdriver or a long ratchet extension bar and touch that with the compressor body (careful of moving belts & parts!) and put your ear to the other side...if the sound you're looking for is amplified (esp. with speed change) then its certainly that part. Bearing noises can best be heard that way.
@afnan.bashir - you're going the whole nine yards tearing down your system! I'm still convinced your compressor is not to blame. The load your vehicle seems to be taking is because compressor is having trouble getting enough refrigerant as shown by low suction pressure; high side pressure shows it can compress fine, as well as some restriction up the line (txv/evap which you're changing, I'm almost certain its the txv and not the evap thats causing this). Lahore is pretty humid these days so the purge/vacuum/charging procedure will need to be pretty much near perfection to avoid contamination with water vapour.
Also as @SER_GTR pointed out, the current dryer needs a divorce.
