maybe you can scan/photo the work order (bill/paperwork) so we can see what exactly was done by the mech. if your bearings are making noise, they are going to be a problem sooner rather than later.
as for the stalling in reverse, not saying this is YOUR problem, but i have seen where the torque (motion) of the motor was different going into reverse vs forward. in that case there was a wire connection that was not so good. often when going into reverse that motion/torque of the motor strained that connection and cause a fault. it was an intermittent problem and drove us nuts trying to track it down. think outside the box, think about ANYTHING that is different about going in reverse vs going forward. like the back up light circuit, this is really a stretch but a combination of bad grounds or faulty connections could do some weird things. with 20 years on that rig, no amount of "up keep" will prevent wires and connectors from degrading.
maybe i missed it but i assume this is an automatic transmission? check to make sure the linkage is not rubbing on a wiring bundle. again, not saying thats the problem, but i saw a case where a clutch pedal would bind on a wire bundle and after 15 years i wore through some insulation and would short things out.
as for sticking brakes, i would highly doubt that. if the engine is running right you can drop it in any gear with the brakes locked and give it gas. only thing that happens is you load the engine but go no where. no if the engine is running like dog snot, fix the engine and the other problems may go away
looking forward to see the work order to help you better