I have a 1992 bonneville with 160,000 miles. Since I"ve had it which is around 4 years now I know that around 70 mph the steering wheel shakes and front end will vibrate. Since the speed limit is around 55 (highway) I keep it around 60 and its better. But one can't help to think that this might be a safety issue down the line. But I have been driving like that for years.

Also the car veers to the right sharply when I release the steering wheel. I wonder if this could be a ball joint or strut issue.

Also the inner back tires wear down very fast on the inside treads. The front seem to last alot longer if thats any help. My tires were balanced the last time I had a flat but I don't think I had an alignment check.

Definately get the alignment especially beacuse you said it veers sharply and that will also fix the tires wearing improperly, I always have an alignment check when I get new tires mounted along with the rim balance

and you might have a bad bearing on the front which would cause the steering wheel to vibrate

Might have a belt shifting on one of the tires. I have had that happen a few times since I moved to Fl. Must be the sun. Feels like the tires are out of balance for a few weeks with a bad pull to one side then all of a sudden it get thumpy even at slow speeds. Or could be the wheels. Do you have stock or aftermarket wheels. Wheels that are not hub centric can shake if not installed properly. My ex GF also had an issue with an aftermarket wheel being so out of balance itself that the only way to stop the shaking at 70ish was to balance the tires on a "road force" machine that simulated the wheel and tire being on a road as it spun.

An alignment is in your near future. When you have that done the shop will probabaly do check of your suspension This should help the vibration and abnormal wear. If you suspect a bad bearing next time you go out listening for a wurring or hum. These are the tall tale signs of a bad bearing.

Check that alignment. You may also have loose ball joints. Check it all for play.

Check your brakes too. I just had an alignment done because Michelle'* 4-Runner was pulling to the left and the front tires were wearing funny. They found the driver'* front brake caliper is sticking causing the pull to the left, low air pressure causing tire wear, and needed a slight adjustment. Good luck,
mike