Changed my mind again due to more information about electric bikes. I decided I'd start a list of required bike parts and underlying logic, which may prove useful to someone else going through the same process.
Goal: a lightweight but very robust e-bike for commuting with high reliability, good cargo capacity, and enough range to help me over those hills.
Bike electrical
Hub Motor (vs Mid drive): you might get lower bang per the same motor power, but there’s a wider selection of hubs, it never needs a special bike frame, hubs can be pretty subtle, and tend to be more robust. If I need a replacement 10 years out, it’ll be trivial to swap a hub motor. With a mid-drive, it might be difficult to replace.
Front hub (instead of rear): improved weight balance, compatible with any gear choice, easy to switch out. Downside: Limited traction for high power (>1500 watts) or loose gravel roads, neither of which are issues for me:
Geared instead of Direct drive: I want a freewheeling clutch to allow me to coast down hills. I’m fine sacrificing regenerative braking for it. Also geared motors are smaller in diameter (less chance people will notice it) and slightly lighter, for which I sacrifice some robustness (direct drive motors have fewer moving parts).
Possible models: Bafang G01 and G310 or eZee.
Motor sensors: Torque sensor to allow for more natural ride, eliminating issues with moving the pedal while dismounted. Makes it less necessary to have motor cut-out from brake signal.
Battery: Needs to have enough excess capacity to be sufficient at 80% charge, and also allow for gradual capacity loss over time. Expected life 4-5 years hopefully. Should be a common connection type to allow for replacement later.
Battery charger: should be able to charge to 80%, which extends battery life dramatically
Motor controller
Motor readout: Speedometer, Odometer, Battery Level and assist level should all be included.
Bike lights: Front and rear, integrated with battery, well fixed to bike or easily removable.
Bike horn?
Bike
Frame: Prefer steel to aluminum. More robust, can be lighter if a good alloy used.
Wheel covers: Side covering or only top?
Wheels/spokes/rim/tires:
Chain/guard:
Brakes
IGH: Sealed.
Carrier/basket
Kickstand: two legged
Security/locks
Drink holder
Pedals
Handlebar lock: collar or spring based. Sick of the handlebars flopping around and grabbing onto me while trying to chain the thing up.
Handlebar grips: Not rubber. Sick of having sticky disintegrating grips. Maybe cork or leather?