OP here. My roof is in great shape so I won't be replacing it any time soon plus it has some interesting curves to it so adding rigid foam and sleepers over the roof deck might be more trouble than its worth. See pic: I do have the gable vents and the giant vent over the porch so I think ventilation in the front part of the attic (the shorter knee wall in the original picture) is ok. I think what I've decided to do is to add soffit vents on the back of the house (where there are no intake vents). Then I'll install a foil radiant barrier on the bottom of the roof deck in all of the accessible attic areas. I will pull down the wood paneling stuff, add rigid foam between the studs in the knee wall as well as the roof rafters, and install sheetrock over it all. Its all 2x6 so I should be able to get 4 inches of foam (R20 or so) in there while still leaving a 2 inch gap for air flow under the roof. I found a guy on craigslist selling 4 inch closed cell foam at 75c per sqft. I've also thought about being cheap and just using fiberglass batts (r16) with baffles on the roof deck instead of foam. That would cost r4 but save quite a bit of money. So long as I make sure I've got a good air seal with the sheetrock and plenty of ventilation, after that, its all down to r value right? I've also essentially given up on the thought of spray foam on the roof deck. That would cost in the neighborhood of 5k plus the cost of ripping off and reinstalling the sheetrock.

If you can purchase it locally, then I wouldn't bother with it unless you have another caterpillar problem, in which case, you can run out and get some. It doesn't keep well, so if you don't end up using it, you'll likely have to toss it at the end of the season. As for the catfacing, there's always a chance that something--bugs, fungus, etc.--could take advantage of any break in a fruit's skin, but most of the time, a catfaced tomato matures just fine. It looks like the one in your pic is scarred over pretty well. The top "pest" that I can think of that might cause a problem in vulnerable fruit is ants, and Bt won't work on them anyway.

The paper is the moisture barrier and needs to be on the towards the conditioned (interior) side of the house or garage. This is done to prevent moisture from getting into the insulation and ruining it. You can't put something above the insulation that would trap moisture. If the joists are above or close to the level of the height of the insulation, then the best option would be to lay sheets of plywood on top of the joists. This would give you a place to stand and store items. If you have blown in insulation you could clear an area and give up some R value. If you have fiberglass batts that are too high, then you could compress them and also give up some R value. If the batts are too high, then you could remove a section and replace it with a less thick batt in the that area.

Thanks everyone for all the great comments here. I ended up getting (most of) the job done. I will say, depending on the size and type of attic you have, it could be a bit of a challenging weekend job, and probably best to not do this alone (like I did). My attic is pretty small, and there isn't an easy way in, so this involved a lot of climbing up and down from, and crawling through, a fairly small space. I wouldn't call this a fun project by any means. And yes, there were lots of spiders, and even some old markings on the trusses from when the house was built in 1850. This was definitely hard work, super messy, and something that I really would have rather had someone else do for me. But... I saved a heap of money, so thats the upside. That said, in terms of the work itself, it is probably best to do this work with someone else, but this is definitely a job you can do yourself if you're up for a good challenge. I did have to run up and down the stairs and up into the attic many times to unclog and refill the machine. The way I controlled it was to set it to "on" and connect it to an extension cord that I was able to bring up into the attic with me, so I could easily turn on/off the system as needed (I found this tip on YouTube). I bought 30 bags of cellulose and ended up getting just over 3/4 of the attic done with about 18 bags. I still need to finish above the master bedroom. I ended up leaving the existing insulation in, and just sprayed right over it leaving about 12-14" throughput the entire space. I opted to not pull out the old insulation and look for gaps to seal, mainly because it would have been an incredible amount of work, and getting rid of the waste would have been difficult without a large garbage bin, and I figured the 12-14" layer of cellulose was in a way sealing the space up already. At very least, it will keep the rodents out, as apparently they don't like digging through cellulose (and I cant blame them, its dusty and kinda gross). I'm hoping to get the last area above the master bedroom done in the next month or so, and then we should see some real improvement in our heating and a reduction in propane costs. Next up - new storm windows!