Racing?
TCR is a race, whether you race seriously or not. Audaxes aren't races but some treat them as such. Trans Atlantic Way isn't a race, but a lot of us treated it as one.
Taking the piss?
I'd be careful about saying that about a rider with a different approach without knowing their reasoning. I can see the benefits of camping and cooking. Better sleep quality makes a huge difference. They may have food allergies, a specific feed plan that works for them, problems with strange beds etc etc. A tent can be erected quickly if you know how and you don't need to hunt it down.
Even if someone isn't doing it the best way possible, knowingly or not. They might be doing it the best way they possibly can. I know that quite a few don't really race. Just as in the London Marathon.
£25 to apply for a place?
Screw that IMO. YMMV.
Riding to the start?
Seemed to work for Lael Wilcox when she won TransAm. I also had an interesting discussion with Ian Walker (N-S cross Europe WR holder) about how he felt that he started going better after so many days into his attempt and whether riding to the start might possibly be and advantage.
W/kg for climbing?
I aimed for <3W/kg on Trans Atlantic Way and Trans Alba (low end of tempo for me, as a guess, as I didn't know my exact FTP). Only going harder when I had to to keep my balance. Hardly ever over 3.5W/kg. Much slower than my peers but it didn't seem to do them much good. I was carrying more luggage weight than most.
As said, improving your W/kg will help your climbing. Don't overlook weight/strength training. I don't have the flexibility to do squats without hurting my lower back (or I just can't do them right) so I do EMS, which is also helping with my flexibility.
Gearing?
I used 28/38/48 and 11-32 for Trans Atlantic Way and Trans Alba. I thought that'd be plenty low enough. I'd have liked a bit lower and I don't like spinning. Steepest hill was about 25% IIRC.
I don't think anyone knows enough to say that one way works better than another. Especially when you consider the variations in routes, weather, different events, different riders etc etc. Always good to see different approaches and ideas.
Best of luck quixoticgeek
(I hope you ignore whoever it was who tried to bully you into silence)