Hill starts are a bit of a problem with my Model 30 City too, its because the brake light switch cuts the power so when you hold the brake on the throttle is disconnected.
I find with mine that on hills its best to hold the throttle fully open and then release the brake, then rolling the throttle off as it pulls away, its something you get used to with practice.
Regarding range, don’t wait for the bike to slow down as an indication of running out of charge as it doesn’t work like that with lithium-ion batteries, they are controlled by a battery management system (BMS) which at a set voltage basically shuts the batteries down, until then you get full lercormance, so its a bit like running out of fuel with a normal engine.
They have to be managed this way as if they allowed to discharge past a certain point all sorts of nasty things can happen such as thermal runaway (fireworks!!) So all lithium ion systems run through a BMS to cut them at a set voltage unlike the old lead acid powered vehicles which would slowly die away.
Glad you are enjoying the Moda, I love my little City for nipping around town.