Yes yes, and maybe.
The switch either tells the actuator to lock or unlock via the relay. It works or it don't. So unlikely it's the switches. You can disassemble the switch and give it a good cleaning, though if you want to keep the OEM switches. The original factory lock switches have the spaces between the "Lock" letters a bit larger than the squished up replacments. You can see the difference if you hold them up side by side. If you don't care, just get new switches if you need them. The actuator may be going bad but that would take further diagnosis to isolate.
But if the key being stiff to operate may be the lock itself, the lock linkage, the door lock on the latch, or a combination thereof. Likely manually operating the knobs being stiff as well, it sounds like it's in need of lubrication or something may be bent/misaligned. Are both sides the same? If so, I'm guessing you're going to be pulling the door panel.
Most of the time, cleaning and re-lubricating everything will get things in working order again. I highly suggest shying away from graphite or oil-based lubes and go with a Teflon/PTFE based lubricant, like Tri-Flow or WD-40 Specialist Dry Film Lubricant. It won't gather dirt like the non-Teflon ones.
Sorry, this is going to take a little time to deal with. Good thing is, you may not have to disassemble everything to clean/lube.
But- if you need them...
2 per car-
Switch p/n 3078509 superseded to 20734310 in 1988.
Relay p/n 20306055
Actuator p/n 22020256 or 22062740
Door Latch/lock mechanism p/n 20594022 (RH) and 20594023 (LH) superseded to 16608234 and 16608235 respectively.