I recently switched to softer bushings on my Lacroix LSSS (80A back, 70A front -> 70A back, 60A front) and it did wonders for me. I still have to check out the top speed for wobbles but so far no issues there.
I always wondered why the bushing crowd online was raving on about it all the time but now I see why.
Which setups do you use?
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:
These come to mind, there are probably more