I’m surprised that Electra finally went away from the old standby 1 piece crank after all these years. The square taper still should give you a ton of options and I have read you can put an 8 speed freewheel on the original wheel. You may need to add a spacer/washer to give it that touch of clearance. I did see an 11-32 8spd on amazon for about $30.
I wasn’t a fan of the grip shifter on my 7D and put a Shimano Rapid-fire trigger on it a long with Shimano levers. I thought the stock levers felt sloppy and rattled.
Like you my knees are in rough shape and the low 1st gear makes any of the hills easier. I can spin…I just cant crank. I have the 11-34 on mine but anymore really don’t need to go as low as 11. The jump from 34 to 24 is a bit long and if I could find a better spaced freewheel that would be an improvement.
Either way enjoy the 7D I’ve really like mine, they are great riding bikes.