Yes, provided it takes off like ARM does currently. On one hand the work being done on ARM right now is helping displace the x86-64 monoculture, on the other hand it might leave no niche for RISC-V to fill.
True, but this is something that could be relatively easy for Arm Ltd to address in an endless number of possible ways, considering their already-dominant position, the perceived seriousness of the threat, etc. Just like Microsoft basically gave up on making the average Joe pay directly for a Windows license.
Another question is, at what point do you expect RoI on your RISC-V expertise, even if it was basically guaranteed to take 20% of the global CPU market 10 years from now, you still need to ask yourself, what do you want to be doing until then.
I'm barely old enough to remember when VLIW was still being hyped, and while RISC-V so far has a much better outlook commercially, it would be wise to remember that this market is ruthlessly competitive. Even companies as old and dominant as Intel must remain vigilant, for the old friend next door may eat their lunch and their dog.
ARM helps RISC-V a huge amount. A lot of the software porting for RISC-V is much, much easier because of the effort ARM has already pulled in. The same goes for other things like ARM Platform.
RISC-V already has lots of niches and its a open standard. Ill be fine.
Place your bets wisely.