I suspect that the implied arrogance of "don't have what it takes" is unintentional, and to deprive others of their sadistic joy at the resulting blood fest, I'll spit out that bait and let it rot on the bottom like it deserves.
Having said that, I know all about do-it yerself maintenance, and have spent untold dozens of hours on rigging, plumbing, electrical, heating, propane system and engine. When the stern tube snapped I wrapped that sucker with two layers of mat and three cloth, and it took us as far as we needed to. But the hull is also cracked, and while I could patch it myself, below waterline fiberglass repairs of structural components is not something I want to bugger with. I am thinking of taking some courses, but there is a four year apprenticeship in composite repair for a reason.
Besides, there are too many sins out there hidden in bottom paint for the next guy to do properly and I don't want to be part of it.
Maintenance items that you list are in fact quite unremarkable and most dudes do it themselves. But replacing a section of hull and stern tube? If a guy does that kind of work and isn't a journeyman glasser, unless you never leave the dock, I think you are taking too great a risk with people's lives.
If it's just your life that's your call as long as they have a good bouy to mark where you went down so I don't tangle with your mast at low tide.
I've always done all my own work on everything from houses to cars to boats and I guess I'm passed the point of "satisfaction" in that. I know I can do it, big deal; it's just another job to do. And I know when the specialised knowledge required isn't worth my effort to learn as well. That's why I have insurance.
The whole point to this thread however (for me) was about separating fact from fiction about the lifestyle of the cruiser. And nobody told me about the 15 grand I would have to cough up if a caught a rope on a prop.