How will remaining XLM be distributed? Have any details been released on more airdrops?
That's the main problem with Stellar: distribution has not ended. Remaining coins can be dumped at the exchange whenever individuals who control the reserved coins see fit. If you wonder why the price has not gone up despite good news that would put other coins in stratosphere - here is your answer.
I would like to know that as well. And also are the remaining coins locked in any way or could they be freely distributed anytime?
That would lead to coin bancrupcy.
Thats why there is "white paper" where coin developers are actualy revealing their plans..That could happen only by software and not monetary character called "hard fork" where the coin is improved by security and many other things.And second, there is community and even institution behind that and thats impossible to happen just like that.
BIG players like IBM have trust in Stellar and NOT to other coins and that is not coincidence.Have that in mind when asking yourself a question is it SAFE to invest..Yes, it is and im sure they know perfectly what they are doing.