Welcome to the dark side. Many trawler owners are recovering sailors who were tired of being cold (or hot), wet, and tired.
Learning to drive twin screws will not be difficult. When the time comes, you will be able to find a good captain with experience giving lessons. The good news is that it's easier to learn to drive/operate a boat than it is to afford one. As an aside, as someone who used to conduct "How to purchase a Trawler" seminars at Trawler Fest's until PMM purchased TF, i noted that sailors tended to want twin screws on the theory that two is better than one, to which someone once said 'if I took care of my engine the way many sailors do, I'd want a backup too!" I personally like single screw boats, with a thruster perhaps. I find they are easier to work on. But it's personal preference - there are long threads on forums like this arguing the merits of one or the other.
I'd hazard an observation that there are four different general configurations, each with their own pluses/minuses. Trunk Cabin (or Tri-Cabin) trawler such as the GB42 and dozens of Taiwan variants; Sundeck Motor-yacht style with a full-width aft cabin (Defever 44, and GB also makes a variety); Pilothouse (Nordhavn 46; American Tug/Nordic Tug; Krogan 42; Solo 43; Ocean Alexander 50 MkII; etc.); and a Sedan/Euro (Willard 36 or 40; GB42 Euro; etc.). Also need to factor in speed vs economy. If you're not retired yet, you may be willing to trade economy for speed - for example, if you are limited by work to long weekends, going 15-knots will triple the area you can cover compared to 8-kts (not the distance, but the area of the circle); though fuel costs will double. Might be a good trade-off depending on your situation.
If you have done 95% of the maintenance on your sailboats, you will easily be able to do the maintenance on a trawler. The systems are not that much different. Trawlers tend to have more room for mechanical installations (especially single-engine trawlers) so access is easier and tendency is less to defer maintenance.
How to value the boat? I wish I knew. I've owned the same brand (Willard) for over 25-years, and moderate the Willard Boat Owners group on Yahoo, so I have a very good feeling for them (example: there is a
W36 just listed that is an estate sale from a very knowledgeable owner who did an impeccable restoration and the boat, correctly marketed, would easily bring twice the $38k asking price, though probably too small for your needs, and on the wrong coast). You will have to decide whether you have tolerance for a boat that is cheap and a bit tired, or willing to recognize that an owner may have made recent desirable upgrades (such as electronics).
Some folks on forums such as these are pretty harsh with brokers - attitude that they are a bit sleazy. Personally, while I've met some like that, the vast majority I've met are honest people who like what they do and look forward to repeat business. Even when I was pretty involved in the business side of trawlers 15+ years ago, I preferred working with a good broker than not, though I view them as advisors who's input I weigh carefully - in the end, they are paid by the seller, so I do not expect them to be my advocate, of course. These days, brokers often have access to Yachtworld records of what actually sold so they can help you work-up comparable values. If a broker won't work with me in that way - honestly and fully - I would find someone else.
Pat, these questions have been rehashed in the archives, but they are difficult to find, and I'm guessing few on this list will mind giving their opinions. But I can say one thing: very, very few converted sailors revert back to sail (I know of one - someone up in your neck of the woods in MI bought a new Nordhavn 57, hated it, and had a custom 50-foot Valiant built). There's something to be said for cruising in fuzzy slippers.
Good luck! And welcome to the list