The battery on my bike is perhaps 2 kg with the bike in total perhaps 26 ish. Removing the battery does not help except for hosing down a dirty bike or preventing theft of the battery.

In Europe a lot of the Bosch/Yamaha bikes have the so-called 'walk mode', where you hold down a button and the bike powers itself up whatever slope at walking pace.

For some reason I understand this mode is illegal in the US, but it makes all the difference over here - especially when going up stairs (or other 45 degree slopes).

My specialized has a walk mode. Not illegal in the states

My RadWagon has a walk mode, I'm pretty big though so never needed to use it.

If anything USA ebike laws are the most lenient in the world

Or an aluminum frame that can deal with being banged around a little.

Your partner might not like what that does to the apartment walls.

If my partner leaves, there's more room for bikes!