Throttle cable question(s)

I wonder if a bike shop would have proper crimping tools if I shortened cable
Nope. They just get a new cable if they cut one too short.

I don't think that ball is even crimped, more likely installed on the cable while it's molten.

I gave up on factory cables and switched to the adjustable Lokar type. They're cheap on Amazon, seems like I paid less than $15 for the last one I bought.