E-touring Bike Concepts

I'm considering converting my old Diamodback Hybrid to a e-touring bike. The frame is reminiscent of the very old Schwinn Paper Boy special. Steel frame and ridged. I currently ride a Trek Duel Sport with the Shimano Steps Mid Drive system. I've used it for bike camping and a self supported Oregon coast ride. Great fun but the aluminum frame flexes Iike no tomorrow. I'm comfortable crusing at 15 mph on the flats but I'm not a hill climber and need the e- boost. Anyone out there e-tour or have advice. P.S. I'm not mechanically inclined.

I'm looking for reliability, simplicity, range, and off the shelf parts. No class 2 features.