Tools, Aftermarket, Custom, replacement donor parts, that's on you. DF has a budget estimator based on best guesses of typical work done. You chose your powdercoating, wheels, tires, seats, aftermarket gages, ect. You have to own that and should have planned for it. I will agree you do need a drill/driver where they say you don't, but that is it. Have I also used a welder and a circular (band) saw, but I have customized my ride.
You picked your car and paid for it's shipping and replacement parts. DF cannot do that for you and are pretty clear that the kit is not the only costs you will face in building it not are they responsible for your choice in aftermarket parts to fit.
I truly think you are nowhere near $35K for your build but if you are, I am sure it is a kick ass ride and once done will be ever proud of it.
All in I am $16K without tools, with wheels, tires, seats, side panels, under trays, wiring, lights, seat belts, and on and on included. I do have a cheap 2.4L auto but the SC/TC guys are only about $5-8K more due to kit and donor costs.
Joe