Pics will help us see what type of lock you have, some are home use types and dont last well at sea.
As to adjusting the rollers, usually a +screwdriver 1/2 turn either way. Keep sliding panel square by opening door slightly about 1/4" daylight top to bottom, adjust until daylight is equal. If you have a problem adjusting it remove the panel. Slide fully open and lift
it out of the track turn on its side (watch your deck
and overhead). You can now lube the rollers and free up the adjusting mechanism.