Okay are you looking at what you are asking?
1. Inspections are simple no reason to make things complicated. If you read my first response you should get the idea. Having the lens in the fender but not hooked up means they do not work so FAIL. Having harnesses should be fine, they are safety restraints. I'm going to assume you have aftermarket H4 style headlights, because the OEM lights are sealed beams. Okay again if the headlight is not functioning then Fail. I have never had an issue with the height of my car during inspections & the rear wiper not being there is not a problem. Make sure you have good wiper blades on the front. Like I said above things have to work & be in good condition.
2. You asked if backfiring is bad then you say you hear it's normal. So why ask the question if you already had the answer you wanted to hear? Yes our cars do run rich, but that doesn't mean it's natural to backfire.
Common causes of backfires are:
- Poor or unregulated engine timing is often a cause of intake backfires, but can also be responsible for exhaust backfires
- Improper wiring in the ignition can also lead to timing issues and backfires
- Low fuel pressure, clogged fuel filters, and weak fuel pumps could cause a severe lean air-to-fuel ratio during fuel injection
- Missing or damaged catalytic converter can result in backfires out the tailpipe
When a driver shifts up and lets off the accelerator, the engine has a moment of running rich. This causes an incomplete burn which causes the fumes to explode in the exhaust, thus a backfire. Now in a lean condition where the timing is to advanced the fuel doesn't have enough time for complete combustion also resulting in a type of backfire.
3. I can think of a lot of other ways to spend money that will be better from a performance standpoint.
I have to ask man, really do you not know how an Inspection works?