The counter school of thought is that the second pilot (owner) can potentially take away from the pro-pilot in terms of having to 'baby sit' an inexperienced crew member. Again all situation are different but generally speaking if the owner wants to be SIC (really no such thing in the PC12 as it doesn't require one per the type cert) then generally a good policy can be put in place with higher limits and aggressive premiums - with an owner listed as 'SIC'. It definitely helps if the owner commits to doing Simcom or formal PC12 school even if he is lower time as then he should be able to contribute to the safe operation of the aircraft in a 'crew' environment and not just be swinging the gear and working radios.

Second question the answer is yes - a policy can require 'two crew only' flight for an SP airplane. Very common with Cessna CJ's for instance which might be used for charter or P91 where the company wants two-crew all times and very high limits of coverages. The policy would be written two-crew only in lieu of SP. The difference in premium however for a two crew policy vs SP will not pay for the co-pilot's salary - won't even come close. So generally the two-crew is implemented if the aircraft owner wants very high limits or it is mandated due to charter ops or something like that.

The solution seems to be a more capable mechanic, not a new airplane.....

If you can afford a SETP then I'd say do it. I wouldn't be afraid of selling an Evo either. They are selling. I had one that I all but had it paid for and someone came along and wanted it more and offered over the asking price. Will it sell as well as a TBM or Pilatus? Probably not, but nothing does.

A TP spoils you. Your Bo is a great airplane but once you go TP you will never want to go back (at least that's the effect it had on my brothers and I).

Also, don't listen to people when they say you can't operate a TP within 2x the cost of your Bo. It just isn't true.

Your Bo probably burns 17gph at 200ktas? Am I close? So that means it goes 11.7 nm per gal.
Avgas local to me is $5.19. So it costs you $0.44 per nm in your Bonanza.
Annual costs are around $10-15k I'm guessing? So if you travel 15,000nm/year then your rough fixed costs for the year are $16,600-$21,600 (and have spent roughly 83 hours in the plane)

The Evo (with the -42) can fly 300ktas on 38gph. That's 7.89 nm per gal.
Jet A local to me is $4.26. So it costs $0.54 per nm in the Evo.
Annual costs are going to be around $3-4k. So if you travel 15,000nm/year then your rough fixed costs for the year are $11,100-$12,100. (and have spent roughly 53 hours in the plane, or 36% less than in your Bo)

There are other things to consider as well like TP reliability, pressure, speed and range, high altitude flight to get around weather, smooth running thus less fatigue, etc. The Evolution is really an incredible airplane. I just wish it had 6 seats.

Biggest differences in costs will be purchase price.

I didn't add in insurance because I haven't looked into that yet for the Evo. That could be the equalizer. I for one plan to not get hull insurance and just go with liability. But that's me, I can afford to do that. From what I understand, there are a lot of people that fly experimental that do the same thing.

sold on it- but it's the cost of capital that makes the acquisition so difficult.
the time will come when there are enough SETPs on the market to drive the costs down to the "twin" realm. (maybe I'm wrong, but I'm speculating because the SETPs are earlier in their product evolution than the pistons).

also- on the certified TPs, it sounds like more people follow manufacturer's recommended maintenance schedules (including cycle items, in addition to hours) which makes them much more expensive to maintain (when was the last time anyone followed the Beech recommended items for an A36?)

I'm not sure why they say a hot section has to be at 1850 hours and overhaul at 3500 or 3600. I had someone tell me once that those are actually set by the FAA during certification and not Pratt and that the engines can actually go a whole lot longer. Again, I don't have any way to back that info up.

As far as items on the airframe and the rest of the airplane itself it's not any different in the experimental world. Parts just cost a fraction of the price of a certified plane.