Oh how fun! We started taking our son camping when he was less than a year old...he is now 3.
We like "Swy Flotter" natural bug spray, it is made entirely of natural ingredients & can be sprayed on the face & won't be a problem if he gets it in his mouth, except probably taste bad...but BE AWARE that bears like it too, so put it away before you go to bed, if you are camping where bears are. (they like the anise, we think...we found this out the hard way...)
I agree, don't worry if he gets dirty, but DO pack plenty of clothes, in case things get wet or muddy...or it's cold. Extra blankets are good too. I remember waking up a lot to check that my son wasn't too cold...until we just put him down on the zero bag, with his sleeping bag inside of it, & zipped him up. No problem after that.
We found that having our son next to us on the floor, on a folded over cushion (eggcrate) was more fun, & less to haul, than having his portacrib in the tent, plus then I could check that he was warm enough much more easily, or if he wanted to crawl in bed with me, he was right there. We used the portacrib during the day, when we were starting the fire, or needed to walk around camp to gather wood, or whatever.
He brought a trike & a couple cars to play with in the dirt, & that was great! I would suggest at least one item, but not much more than that, since there is a lot to explore, & you don't want to detract from that.
As far as the falling asleep & the campfire, just use your best judgment, I personally would let him stay up & enjoy it, if he falls asleep, then so be it but then he gets to participate in the fun that you love, too, & can sleep on the way home, & when he gets home! What we find is that our son stays up the first night, then the second night of camping he is so pooped, he will fall asleep in my lap (which he almost never does at home) & sleep thru whatever loudness ensues.
Have fun, take lots of pictures, & get dirty! You can never substitute the memories...