Body work questions?

Well, I have been working on my 88LX for a while now. I am trying to smooth out the body due to old paint job, hail damage, rust and I just don't want it blue anymore. I am trying to do all this on a low budget. It is currently about 75% primer gray now, with all the rust ground to bare metal and covered. I didn't strip off the old blue paint, I just used Bondo spot filler where I ground out the rust spots.
I just have a couple of questions. I have been doing minor body work on my own cars for about 10 years now, but I am trying to do "good" work this time. The only part that is not primered right now is the hood and top. This is also the only place that has hail damage. What would be the best way to get rid of this? Will the spot filler work, or would it crack after a while? I am also going to hold off on a real paint job for a couple of years and just keep it primer black. Is there a good CHEAP sprayer out there? I would go through quite a few cans and they don't spray good on the hood and top. Also, will the primer fill small scratches? I had to use a putty knife and heavy grit sandpaper to get rid of my pin stripes and I have some sanding marks now. Should I fill those or will the primer fill that in?
I also posted last week about cleaning my headlights. Mine are too far gone. The mirror finish inside the headlights still looks good, just the clear lens' are nasty. Is there a place to buy just the clear pieces or do you have to buy the complete kit?
Thanks in advance, and remember I'm poor(just on a low budget).

Yeah, so far everthing that has primer on it has had a good sanding to get rid of old clearcoat and give it a good bonding surface. Its also the best way to find those little dings that your eye doesn't catch. All my rust spots have been about marble size or a little bigger, so I used a surfacing disc on my dremel and got it down to bare metal, then applied a "rust treating" primer followed by the spot filler to make it flush with the painted surface around it then primed again.
This may sound stupid, but I would assume that to hammer out the dings on top of the car I will have to remove my headliner and access from inside? Bah, that sucks.
So, should I use spot fill for the sanding marks left by the really heavy grit stuff I used to get rid of my pin stripes or will a good primer/filler take care of that? I will probably keep the primer on about a year or so, until my father in law gets an air compressor so we can start learning to paint
I would think if I keep a close eye it and not let it rust it should be ok. But I guess I'll see.