Yes, all these small mobility scooters will fit in a car boot but will take up most of the space of a standard sedan/saloon sized boot/trunk.
These scooters generally disassemble into 4 parts; The seat, battery pack, front and rear wheel section.
Yes you can. Ideal for the bus, train and Luas. You can also bring them on a flight.
The speed can be controlled and the fastest they go is 4mph (6.4kmh).
This varies depending on the model but it's generally between 252-322lbs/18-23 stone/114-146kg.