My known problems are: 1. The last few inches
: of each strip are problematic.

Dan, sounds like your auxillary fence is too short or you are moving to the outfeed side too late. I would try skipping the push stick and pulling the last 2-3 feet through the saw, with that much of the board still in your fence/featherboard rig you will have a better idea of which direction you should be pulling the board and more control once it leaves the aux fence. If this doesn't improve your results then try a longer aux fence.

: 2. My blade (DeWalt, 8.5" thin kerf, general purpose) leaves marks on
: the strips.

Easily sanded sawmarks are the norm here, but if they are uneven or some are very deep into the strip slow down your feed rate- a binding blade gets hot and wobbles until it cools a bit, if that doesn't help check your saw for blade run out. Turn off and unplug your saw, run the blade up about 2" above the deck and try to wiggle it left/right, you should not be able to move it. If that seems ok, plug it back in and watch the blade when you start the saw, any wobble or wandering left/right will need repair before you will get decent strips.

hope this helps,
Tom