All a matter of which projects you join and the opportunity in them.

I find at the start of an airdrop or ICO they're all a bit hit and miss as it is so early in the project's development overall, but I've definitely had a few now that have worked out for me, so I don't see the downside of being involved.

There are a few things with Masternode coins - you're really looking at both the quality of the coin itself and the state of the market as far as whether it is going to be worth it.

I don't know that I necessarily worry about the question of being 'mined out' as in general this is something that doesn't happen - what is likely to happen though is a split etc and the creation of new coins, which is fine but obviously affects overall coin value. Doesn't necessarily make a difference if the other two things above are okay and you're in it for the long haul on a good project...

As you say, ambitious but looks like an awesome project!