Electric tricycle

I just joined. Nothing special about me, except one thing: my balance is less than perfect, mounting and dismounting is tricky.
I thought of two alternatives to my 26" Schwinn: a tricycle (electric or amenable to accept a conversion kit) or a low bike - 15-16". I see a lot of electric low two-seaters in the street (a large rack/box could be put there, or an additional battery), I even visited a local shop that sells them but the sales girl speaks only very primitive English, and I don't speak Cantonese or whatever. So, my questions were unanswered. That e-bike looks more like a moped than a bike and sells for $600. The ones which look even more mopedish sell for $800-$900. According to the girl, the range is up to 30 miles (perhaps with active pedaling which I don't mind). The bike has a derailleur too. I think if you pedal and/or go downhill, the battery is charged; yet it's only a guess. If so, the pedaling should be harder (on top of 15" wheels).
A tricycle is available today, but... why do they make them so wide? It's awkward to ride, impossible to ride on narrow trails, and awkward to park.
If anyone ever have seen a narrow trike (the width of my shoulders or about will do), please let me know.