EWI to MainStage for marching band

Audio Idiot & Band Director here, I’m looking to hook up a EWI or digital saxophone to MainStage on MAC and run an electric guitar sound on it.

1. Is this possible

2. Would it work instantly/close to zero delay?

3. Would I be able to amp this/hook up to sound system to play live for Marching band show?

4. I have a student with an EMEO digital sax that works with midi and stuff, would this function for my needs or would I have to buy a Roland Aerophone?