why do you have to MoT it and insure it? You can fill in an SVA form, pay £55 fees, no need for MoT, insurance.Still ...by the time you MoT it road insure and tax it, buy it............and pedal and rest if needs be (as above), I really can't see the point in electric bikes.
Mopeds are exactly the same even down to pedalling them BUT they have a range of hundreds of miles and are much faster if needed. Most importantly they are much cheaper 2nd hand too.
The only requirement is to have a legal bike before adding a throttle.