I don't see these as being major concerns. There's a lot of real use right now and it's overcome those types of challenges.

The idea that something will displace Bitcoin is the more likely concern, to me. However, if someone develops a superior technology it will be because we've created enough value in Bitcoin to make that worthwhile. Also, this community would likely be early adopters of any new superior money technology, so I wouldn't be too worried about losing everything because you went all in on Bitcoin.