Help Please!

Several months ago, my 93 Camry started vibrating while idling, worse in reverse. It also starts vibrating very bad when I get up to 60 mph, but when I reach 70 mph it mostly goes away. It all started when my husband replaced the first motor mount. I kept waiting thinking that maybe the mount just needed to settle, but it kept getting worse.
My husband replaced another mount that was broken and checked the others to make sure they were okay. The new mount made no difference at all. Now he is thinking that maybe when he put the first mount on maybe he did something to the axle or something when he jacked it up.

Also, not long after I purchased the car back in May it started smoking when I crank it. The car only has 94,000 miles on it. I called to see
how much it would cost to have the valve seals replaced and of course it it very costly. One shop did tell me that it might not be the seals, that he had never seen a camry come in to his shop that needs the seals replaced. I named a couple of different things that it could be.
What is strange, it seems like if the car sits for more than 2 days it doesn't smoke, but it will smoke if it sits from a couple of hours to 2 days.

Does anyone have any ideas what my problems could be?

Thanks,
dozemp