The moaning clubs that voted to end the transfer window early are a bunch of idiots. After the transfer window closes, they will see the rest of Europe picking up good players at decent prices once the English transfer premium is taken off the market.
I don't think so. Clubs can refuse to sell and with good reason too. They can't sign replacements, therefore they will not sell anyone they need for the season. A bid does not compel a club to sell. And if the other club is really insistent, they can jack up the price to a "no brainer" level i.e. slap on a 50% premium for not being able to replace the player.
In any case, it's not like clubs didn't realise this would be the case a year ago. Everyone knew when the world cup was and should have gotten their transfer business done earlier. if clubs can arrange and complete transfer deals in January, they certainly can also do that over the summer.
Additionally, clubs can still do deals at any time. They just can't transfer the registrations until a transfer window. So clubs just need to tee-up their transfers early, and then rubber stamp them once the windows open. Any clubs moaning that the short transfer window has impacted their ability to do business is just finding an excuse / scapegoat for their own failures.