Those all seem like real concerns for the future.
I still think the main present issue is that the average user has a hard and complicated time keeping their bitcoins safe and therefore are not willing to seriously move any wealth into them.
But in the little bit longer term the confirmation limit seems like a real issue. Is it 2.7 transactions worldwide? That is obviously waaaay too little. The needs to scale a lot if that is the case.
2.7 worldwide indeed. That's what plenty of people are having a good squabble over right now. Multiple solutions are on the table. We'll see what transpires relatively soon.
Some argue that the blockchain should only be a means of settlement and other layers will handle the day to day transactions. I'll let people cleverer than me decide.