I agree with getting something going as a first try concept, then seeing what would be an improvement when you're done. You seem to be having similar problems to my own, that everything sounds like a good idea to try but you only have one "shot" at it.
For example, you could build your first one this year. Decide what is right, what is wrong, DC or ICE, FWD or RWD, 1 person or 2, etc. Try to save $1000ish over the winter, reuse some of your parts from the first build, and upgrade it. Rip out the ICE and install a basic DC setup, then the next summer invest in better batteries. This would give you time to balance the weight of the batteries for center of gravity purposes, etc.
Remember, if you are to build just a simple, usable reverse trike, you would already be ahead of so many dreamers, including myself.
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