score:2
It is largely dependent on where you are. In general, the US take a more relaxed approach to skateboards and do allow these to be brought onto flights as carry-on. However many airports in the EU see the skateboard as a "blunt instrument" and don't allow them regardless of the stance of the airline.
See this article: Can You Take a Skateboard Onto an Airplane to Travel to Another Continent?
I would recommend searching specifically for experiences at any airlines/airports you may be traveling through and take a cautious approach when traveling through the EU.
Upvote:3
No, this seems to have changed. Apparently your trucks could be weaponised.
Checked luggage is rarely stolen, the bigger risk seems to be it going to the wrong airport. If you're worried about theft wrap your bag properly so it's more hassle than it is worth.
People who steal normally are more interested in macbooks and other such luxuries