While X10 isn't a wiring substitute, it has "controllers" available which can control multiple lights and only need 1 piece of romex (or conduit with equivalent wiring) run to it. That would be a good option for the issue of several doorways with multiple switches. I have several of these and the x10 run thru the logs would be much simpler for him. As stated, the controller has to talk to another light switch or module located elsewhere with the regualr wiring supplied to it.
The other benefits like remote keychain control or computer interface, alarm system ties, etc. are a plus in my book.
On the subject of drilling logs, put a shingle nail in the floor where the wiring will come up thru for each outlet, switch, light, run to the second floor, etc. Use a long level to draw a pencil line up the logs from the nail, this will establish the point to drill. Drill far enough back in the log to be behind the deep box dimension. I did this up 2 stories and it works well. I'd advise to drill each course in case you miss one (I only did that once, and had an extension that saved the day for me)...It also helps insure you locate the screws or lags elsewhere. You can make a nail on wooden jig for routing electrical box outlines into the log later. A small router will get you the box outline profile, a decent forster bit and a chisel for cleanup will make box holes in 3-5 min each with a real clean look.
It isnt a substitute for wiring. Its basically a remote control system that uses power line carrier on the house wiring for the control circuit. 
