I would personally focus on Sony and JVC. Epson hits a price point for the money.
Yes, conduit is the recommendation for any pathway that is otherwise inaccessible. Not sure how your wall is setup and where studs run, so it may, or may not, be possible. Every installation is its own can of worms. But, for true future-proof installations, you must have retro access, and a 1.25" conduit is the smallest that can reasonably work. Still, I've done work where I shot wires behind and around finished walls to unfinished spaces without the need to cut a single hole. So, it all depends.
For a projector, certain features matter a bit more than others, with contrast being one of the most important. Unfortunately, advertised contrast and real world contrast are completely different. LCoS remains king, DLP does a good job with cheaper models, with Epson's UB series falling between DLP and LCoS, and the cheaper Epson models having the worst contrast. But, Epson doesn't suffer from RBE issues (rainbows on DLP), that some are bugged by. LCoS doesn't either, but the LCoS products carry a price premium.
JVC and Epson render a half 4K image with eShift, and while sharp, and better than 1080p, they are not as sharp as the DLP models or the native 4K models (better Sonys & newest JVCs).
The Epson models don't support full 18Gbs HDMI yet. Neither do the Sonys. JVC does and the cheaper DLP models do as well.
The JVC RS440 can be had for around $3,000. The Sony models are a fair bit more and there are new JVC models that are native 4K that should be competitive to the Sony models, and perhaps better overall, but won't be priced less really.
I consider the RS440 to be one of the best performance to value ratio projectors out there right now.