Pin holes are rust spots that actually go through the panel right? (or something along those lines? I don't see anything of that nature, you think I'd be alright?
Pinholes are not always easy to see - media blasting finds them pretty quick. My personal preference is to get it back to metal to see what you have. Of course, money, time and the will to take on the big job usually dictate how you approach the job. Personally - I've accepted that I wont drive my truck for 5+ years... but I take pride in every step along the way - and try to do the job somewhere between affordable, and right!

I didn't know one was supposed to prime before laying filler! (thank you for enlightening before I made things worse!

)
Careful how loudly you shout that statement! That's an ongoing debate which seems to have just as many pro priming before filler / as there are pro filler before primer. You'll find MANY threads on that topic here.