I do think a lot of the stuff you mentioned where really good ideas! Don’t worry though, i will always do what i think is best for the game just like i have up until this point :)
Have you managed to complete the game? :D
I passed the Day 75 raid, now I'm waiting. I don't know what else is supposed to happen. I didn't get any notification saying I won or that there was another wave scheduled. It's currently Day 91. I'm actually letting it run right now as I write this because sadly there isn't anything else I can do for my island... I'm maxed out on space and resources.
Yes, I lost my castle, which gave me some kind of defeat screen with a score, but after I got a victory screen with a different score. After a few screens (an epilogue screen, a thank you screen, etc), I was back at the main menu. I chose to reload, replayed the game from day 95 onward and successfully protected my castle, after which I also got a victory screen.