RX7Club.com - Mazda RX7 Forum - New rx7 owner with a few questions!!

so i recently bought an 88 rx7 gtu n/a, completely stock all the way down to the spare tire and jack!!
when i got it everything worked fine other than the sun roof (motor works fine, i think the rails need to be greesed), and the clock doesnt really work all the time.
It was also RIDICULOUSLY slow. my budies 80's corona beat me... completely stock. after a few sea foam and water treatment sessions though, its starting to pick back up. It also had a huge vibration issue.
So i have a few questions to ask but before i ask them, know that i did search all issues for hours with little to no luck.

1. I know rotary motors are supposed to rev real smooth, but ever since i've had the car, its had a pretty bad vibration when getting to higher rpms. it almost seems like it could be coming from the tranny. it starts around 4k and continues all the way to redline. it almost feels like it starts pulsating, or like something isnt balanced. the previous own told me it is probably a worn motor mount but im not sure. he also said he did a clutch job recently.

2. the other night i took the car out for some rain sliding to see how she handled, and i must say, she handled well for lacking so much torque. for some reason while driving, i realized that all my gauges but my speedo stopped working, including fuel, temp, oil, and voltage. i then stopped the car, pulled the ebrake, and opened the door to see if the lights on the dummy light panel would come on but they also stopped working. the lights on the ash all work but the gauges them selves ont move.

3. also, after sliing a little, i noticed that now when i turn my car off it kina stays running for a good second or two. has any one else ever had that problem?

other than that an the sun roof, the car is in great condition. nothing leaks, ac blows cold, heater is hot, power steering is amazing (not used to that) and is reliable. couldnt be a happier owner=]

thanks in advance for all your help!