Marc J. Zeitlin
On a different Long-EZ (a very nice OSH award winner), I'm in the process of replacing the ancient Rocky Mountain EMS with a Dynon EMS (along with a Condition Inspection, landing light install, and a few other things). This plane was built with extensive use of wire protection sleeving, such as:
While pretty, it is not necessary to cover every wire in the plane (or at least 90% of them) with this stuff. It doesn't weigh nothing, and it complicates maintenance, repairs and replacement. Judicious use of either of these, in places where chafing MAY occur (passing through bulkheads or other pass-throughs, etc.) is welcome and desired. Other than that, though, it's overkill and will just make your life difficult down the road.
Assume that except for primary structure, you WILL have to maintain/remove/re-install/replace EVERY system (electrical, hydraulic, mechanical) on the plane a few times during the time you fly and maintain it. Make that maintenance easy and simple, and you'll be more likely to keep your plane in good shape and working well, and less likely to ignore things. When installing something, ask yourself how much of a PITA it would be to remove it - do you have to disassemble 1/2 the interior to replace it? Anywhere a nutplate would make life simpler than having to put a wrench on a nut on the backside of something, use a nutplate. Have generous service loops in electrical bundles so that wires can be moved, just in case. Etc., etc., etc.