Ford Nationals - Areas for Improvement

The car ran near flawlessly and I'm proud to have built something to make the trip.  There are always was to improve and I'd like to think through some of those so I continue to improve the car.  The things that come to mind include:

1) I need to get some stiffer rear springs or find out what is going on with the passenger side rear tire.  It continues to rub the quarter panel.  It did it a few times on bridge transitions on the highway.  I can just see it destroying a tire.

2) Car tends to follow uneven areas on the highway like grooves.  It also gets rather sketchy when there are a large amount of unlevel and bumpy areas of the road.  I'm not sure if this is just the manual steering or the low profile tires.

3) Once it started to rain especially hard, I noticed leaks which seem to come from the wiper arms  and then all around the top of the windshield.  I don't think I installed new gaskets around the wipers arms which might explain some of the problem.  I'm not sure if the windshield is no longer sealed or what might be causing the windshield to leak.

4) The passenger door is a little difficult to open.  I think this is primarily because the portion of the latch mechanism that is mounted in the door jamb is not aligned properly.  I've tried to change it before but the screws which hold it in place don't want to budge.  I'll have to work on it again.

5) The left turn signal indicator on the instrument cluster does not light up when the blinker is on.  I imagine the bulb is out which is simple to fix.

6) There seems to be quite a bit of vibration in the drivetrain.  It is nothing I have not felt in the past.  It is just noticeable after hours of driving on the highway.