should I suspend a floor-standing turntable?

Toxic,
Where are you located? I just happen to have a very good sounding for the money 4 shelf rack that is a definite step up in sound vs. my own super solid built wood rack with spikes on both. It also sounded considerably better than a custom wall mount shelf I had. I was very surprised at this fact. Would sell cheap because I now have a pretty darn expensive and awesome sounding rack which I'm currently having made into 2 shorter ones very soon. I'm in the Chicago area. I don't have the boxes it came in so local would be best. Plus all the rods are already filled.

Put a few very heavy concrete paving slabs stacked on a sturdy table.
Optionally a slab of maple.

Go ahead and mount it on the wall. Most wall mounts are secured by 4 screws that go into the studs. A little puddy and paint will fix the wall "if" your landlord finds out and insists that you take it down.

Unfortunately I live in Southern California. Thank you for the offer though Dorkwad.

and @Brf I live with my parents (I'm a student) and I don't think they'd let me do the mounting, hah.

At this point, I'm considering just buying a block of maplewood or granite and somehow affixing it the floor. My desk is quite wobby as well, and there's not really a place to put a turntable. Does anyone have suggestions for places to acquire such wood blocks for cheap?