I recently bought this car and have a few issues that I could use some help with:

1. The transmission likes to slip down from 3rd to 2nd or from 2nd to 1st when I coast along not stepping on the gas. I know its supposed to downshift automatically, but it seems to happen too quickly. It doesn't happen all the time and none of the lights are blinking or staying on, so I'm pretty sure it wouldn't be the tcm or tcu. I was wondering if it may be worth it to change the shift and lockup solenoids on the tranny or if I could just clean them.

2. I just put 16" rims on it, a step up from the stock 14". Now when I drive down the highway at higher speeds of 60-70mph the steering wheel starts shaking. I am hoping I don't need to change all of the suspension or steering components due to the increase in wheel size. Could it be my rotors?

3. It has a tough time cold starting...whether in hot or cold weather. Its a recent thing thats happened in the past two weeks. Also when I start it cold, the rpms like to dip down then rise back up until it warms up. Another thing I noticed was a very small miss as it tries to warm up. I changed all the sparg plugs, wires, seals, distributor cap and rotor and it still does it, but only when starting cold.

4. Last thing is my brake lamp indicator light comes on randomly. All my lights work just fine, checked the bulbs and the brakes and everything seems to be working just fine. Its not the e-brake light, but the brake lamp indicator. Oh and my cigarette lighter does not work, checked all the fuses and they are good, everything else works, so I don't think its a fuse because then other things wouldn't work.

Any help would be appreciated, since I am new to hondas and imports in general. I can do most easy repairs myself, so any money I can save by something quick and easy would be great. I was also wondering if there are some easy ways to improve acceleration withough doing any major modifications. I'm not a racer, but I do like to have some sort of oomph off of a stop sign or a red light.