re: Blowing in insulation: how difficult? And how much would it suck in June?

If you decide to blow in insulation, I'd recommend you go get some spray foam and seal the gaps between your top plates and sheet rock. I found my insulation had turned brown/black in these areas due to all the air leakage over the years.

I bought (72) 30lb bags and it took about 10 hours not including setup or clean-up.