To the OP, it sounds as though a lot of your concerns could be eliminated simply by becoming your own boss as an electrician. You probably feel at a visceral level how easy it would be to do that. The chance of success in the trades is a lot easier than in what you are proposing as a frame builder. You would feel less used if you were your own boss, and you can deal with the boredom by hiring others which is the route to real wealth in the trades, along with figuring out what is the sweat spot in your trade and going for those jobs over and over. The richest guy in our neighbourhood who has waterfront property gallore, and a huge yacht, is a guy who does evestroughs, He franchises the trucks, and they show up, roll out a 30 foot piece from a roll of Al, and go up two ladders, 300 bucks.

Then you can reserve your hobby for your private time.

If you want to go ahead in some unpaying hobby field, find one without liability, unless you intend to have no assets, or don't at least have them now. If you own your house and car clear, don't take up framebuilding if you have a family to support.