Since solid body electric instruments don't rely on the surface of the instrument vibrating to produce sounds loud enough for a listener to hear, the finish is less critical to the sound and more a matter of what you like the look of.  So I wouldn't worry about trying to replicate antique finishes intended for acoustic instruments unless you really want that look.

Personally, I tend more towards electric violin (though I do like my acoustic as well).  I've done a bit of tinkering, so I'll offer a few thoughts.

The C-bouts on the acoustic violin are there to allow you to get the angles you need with a bow.  My own (storebought) electric has body in part of that space on the G string side and I do sometimes end up bowing the body when I mean to be bowing the strings.  You don't have to have C-shaped cutouts for that, but you do want to check and make sure you'll be able to bow ok.

Doing a cutaway so on the E-string side your hand doesn't run into the body completely *rocks* in my opinion.  Some violinists do count on the body being there as a cue for their hand when finding the very high notes.  But being able to reach the whole fingerboard easier is strictly a good point, in my opinion.

It looks like the "scroll" section of the neck on your design doesn't tilt back much.  You may have some problems with the strings having enough pressure against the nut to stay in place without buzzing.  There's ways to fix that without changing that angle, if you like the look, though.  You can use a little bit of metal or something to hold the strings down up above the nut, like they do on some electric guitars, for example.

Magnetic vs piezo pickups.. Well, magnetic doesn't have to need any sort of preamp or etc, really, and piezo will.  They sound different and they respond different, though.  The thing with magnetic pickups is that unless you get them really close to the string, violin strings don't have enough mass to put out a lot of signal.  Looking at the ones you posted a link to, they look like they are probably high enough that it isn't possible to play using the whole neck without the strings hitting the pickup.  Since the pickup is kind of strapped to the upper fingerboard, it looks like it wasn't intended to allow full use of the whole fingerboard anyway.  If that's a limitation you're ok with, then it could be alright.

If you go with magnetic, you'll need a steel core string for the heavier strings, since synthetic cores won't have enough metal to them to give much signal.  So your string choices are more limited.  Also the way a magnetic pickup works, it picks up sound mostly from the movement of the string up and down over the pickup.  A bowed violin string is mostly moving side to side over the pickup.  So the sound you get when bowing can be quieter than the sound you get plucking or when you lift the bow off the string and let it sustain for a moment.  Not saying that isn't a usable thing, but it is just about backwards from what you'd expect from playing acoustic violin.  LOL

Piezos act more like an acoustic violin, but pretty much all need preamps to match the impedance to most amps or mixing boards.  They also have the (in my opinion) mildly annoying tendency for often getting a little "zip" sort of sound when you first start moving the bow, because they'll pick up the movement of the string even before it would be sound as we normally hear it on the acoustic violin.  Switching between the strings also can take a little more attention on electric to get it to sound as smooth as it would on acoustic. 

You get used to such things, but they will always be a clue to a listener that they are hearing an electric instrument, not an acoustic.  The sound is different and some techniques you know from acoustic will work less well, while some will work maybe a bit better.  Electric is a different instrument, much like it is with guitar.  Hopefully you aren't expecting it to be able to sound exactly like an acoustic, or to play exactly like one.  

All that said, I think your project looks seriously cool, and I applaud.