Hi.
Yes you can use the Rocktron Banshee with the PSR-295.
Although I am not intimately acquainted with the PSR-295, you can take an output from the keyboards headphone socket, and plug it into the guitar input on the Banshee. You will need to stard with the keyboard volume right down and gradually increase it, till you find a setting that sounds good though.
I personally find the Banshee really underpowered though. That's just my opinion though.
I am actually working on a design for a MUCH improved talk box, in conjunction with a very successful recording artist, and talkbox virtuoso.
Yep. Just treat it like you would a guitar.
yes