Bob, I made a similar mistake with my first ebike. I have always ridden bigger bikes, so I bought a 29'er and converted that. Everything went incredibly well, everything but my ability to swing a leg over the back of that bike! Also, with the seat height set properly, touching the ground at a stop light often made for a pretty dicey situation. After riding it for a while thinking I might "get used to it", made the same decision you are making, time to replace that bike. Not because I disliked it, but because it didn't fit (and yes, getting older DID have something to do with that!).
I ended up with a 26" bike for the simple reason I figured I couldn't get much lower than that without really limiting my choices. Love this bike.
I tend to migrate towards mountain bikes for their sturdy features, knowing full well that about any bike I buy is going to be modified/set up with after market parts for an upright riding position and comfortable seat anyway.
Bigger tires ride better, but you pay the price with poorer rolling resistance. 2.00 width is the compromise I settled on. This last bike came with 2.3's on it, and after switching to 2.00's (because of a tire problem) I find all else being equal, I can ride with the next higher gear with no more difficulty, translating directly into increased battery range on a charge/increased efficiency.
Suspensions, if they are to work right, need to be tuned correctly. This is true on everything they are installed on. Fine if you are up for it, but many try to ride them as-is and are disappointed. They ride around on them while they are totally collapsed, or so stiff they are useless. I'm not so sure I see the benefit, so I prefer a hard tail, with a front suspension only. Even a junk front suspension works better than no front suspension IMHO. -Al