Hi Ken,
You should be able to get more than 7 years out of the system especilly the filter. I really am not familiar at all with that cartridge filter but obviously something isn't sealing right. In general that means bad seals. On the pump motor, that noise could be either the water pressure seal or the bearings. If the pump is out in the weather then possibly moisture has gotten in and rusted thtings up and in that case you'll probably destroy things trying to pull the bearings off, especially the pump end. If it's the pressure seal that should be pretty easy to replace. Repair or replace? If the pump looks clean, no rust, then a repair should be considered. The buzzing is probably the centrifugal starter switch and the thread below gives some insight. Hope you can view the pic. Or, maybe the thing was just frozen up too much and you freed it.

http://www.poolforum.com/pf2/showthread.php?t=4800

Al