For android users: Get osmand from f-droid instead of the google play store. When I installed from the google play store I ran into an map area download limit which does not seem to be there on the f-droid distribution.

I'm pushing 30 and I would say no!
I have met some people over 40 happily riding an EUC so I don't see why not :)
The important thing IMO is that you ride according to your capability to handle sudden events.

Do you have experience longboarding? If yes, I would definitely recommend it.
When people ask me about difficulty, I always recommend them to do a little bit of longboarding beforehand.

Some skills I find useful:

• being able to shuffle around your feet on the board while riding (swiftness when taking off in traffic)
• confidently riding over bumps and holes (overall confidence, also means less muscle strain)
• being able to footbreak, if ever at some point electronics would break (peace of mind)
• knowing at what speeds you can jump off comfortably (safety)

These come to mind, there are probably more