This is the most "fuck this i'll make my own" thing i've read in a while. I like this! I hope you'll be able to achieve your goal of a really lightweigh DE on wayland!
Time wise? About a day. I haven't started writing my own components for it yet, though. That's the next step. Right now, I just needed something that works and I wanted to see if I could do it at all. Now that I've done it, though, I can start making my own components either from scratch or by forking.