Don't sell the car because of the little things getting to you.
You'll regret it!!!!!
I was the king of bad things going wrong back when I owned the infamous MR '99 JRSCed Ls Teg.
About 3 months before I sold it I finally got every kink worked out.
Sucks because now I'm kicking myself in the Ass for selling the car instead of the Si.

Thats a sweet EK Bro, Nice Color, Looks like you have a ton of man hours into it, and the Money..........Damn!

As for the tach bouncing, Try to check your ignitor in the Distributor.
This has happened to me three times now, Twice in the Teg. and once in my Si.
They just go bad with no warning I've found.

Good luck and if you need any help with the little things, PM me.
Maybe i can help in some way.

Peace, -Jeff