Questions about Casio Ctk-3500

Basically, it is well suited as a starter model. The keyboard is normal-sized, which means you learn on the right keys from the start. It also has 1 octave more than many cheaper models. The biggest flaw is the lack of "weighting" of the keys. If you want to play on a real piano or a bigger keyboard later on, you will have to get used to it!

It has a 6.3mm jack for the output.

No, the charger is optional.