This isn't the case, your wallet is not tied to your Facebook account.
By not being an incredibly shady company in the first place? Am I just supposed to disregard everything FB is notorious for, just in case any concerns I raise might be FUD?
It’s pretty clear this is an attempt to take advantage of network effects and dominate the market early.
There is also no guarantee that while FB will be one many validators, I dont see any hard limit on the number of validators required for the network to be operable. So over time a single validators could take over. No one will bother changing coins in this case though as it will be too inconvenient.
How will they kick out the existing validators?
To your question, not necessarily kick them out intentionally, but if the companies that back the hardware to validate transactions fold, are taken over or pull out of the venture, then the number of validators diminishes and you can end up with something resembling a 51% attack [1] which gives a single corporation total control.
This is a problem with all crypto’s unless something is special about Libra which is possible I guess. Then again, even in this case, the dominate player(s) could change the protocol to work in their favour removing the need for x number of validators present.
[1]https://www.investopedia.com/terms/1/51-attack.asp
Given Facebooks quickly diminishing popularity, I’m not sure this is ever going to really workout anyway.
Nice try, Mark!