850 Motor Mounts

1995 850 GLT 100K
Having replaced the right passenger side and top motor mounts I have been checking out the others, trying to fix a persistent vibration being transmitted from the engine bay at idle, particularly when in gear at a light or in park. I notice that the rear center motor mount has two clips embedded in it, on my rig one of those clips has popped out of its seat and is dangling by the rubber band that links the two together.
1.) What are the clips for? Does the clip dislocation signify that the mount is worn and needs to be replaced? Should I just cut the clip loose and run with it as is? Would this be a source of the vibration?
2.) The top motor mount is the poly unit from IPD and it is bored off center, in other words, so that it works like an eccentric cam. Anyone else have experience with this? I don’t know if it is supposed to be adjustable or is defective, and if adjustable, just where should you adjust it? I positioned it so that the mount pin would be as far from the firewall as possible. I still get a sharp bang from the engine bay when I start it up, it sounds like something is shifting violently into position. It’s been doing this for a long time, I just got tired of letting it go, something needs to be fixed.
3.) Anyone have experience with changing the big lower front and rear motor mounts in an 850? Any tips? It looks like a real bastard job since the entire engine sits directly on top of both mounts. I have the typical garage access, ramps and jacks so there isn’t a lot of room for this garage mechanic to manuver. It looks like you just about have to pull the engine to access these things.
I’m pretty fearless when it comes to working on my daughters 1991 240, but I’m a bit more reluctant when its my primary transportation that’s laid up for a week while I try to fumble a solution with make shift tools. I have replaced the PNP switch, thermostats and tuneup stuff, but I haven’t tried to tear out anything with a gasket on it yet. I’d turn it over to a shop but it looks like one of those $1000 jobs and right now it’s just annoying. I’m afraid that if I let it go it will be causing more wear on the rest of the drive train. Thanks for any answers on any or all of my problems.