For power tools ryobi is probably the best bang for your buck option. I personally prefer Milwaukee tools but they are a lot pricier and I justify it by doing a LOT of work on my house DIY.

Consult an electrician or read your local electrical code, you should find all the information you need there. I recently ran conduit from our house to our garage for a subpanel and we buried 1" rigid conduit 18" below ground. It's a PITA but is up to code, safe, and should last a very long time.

My experience with painting/priming has universally been that the more ideal the conditions/preparations, the better the quality of the final result. So I would vent the room or use a dehumidifier or something to get the humidity down just in case. You don't want to prime everything and then have to redo it because you skipped a simple step.

Wood glue is very easy to work with and is the best option for gluing wood hands down. The glue joints end up stronger than the wood itself in most cases. Just make sure you use some clamps, or at the very least lots of tape to hold the pieces together tightly for a day to ensure the glue joint sets up properly.