The server cannot be split because to make new servers requires hundreds of high-spec machines to be available for purchase, which they are not because of the semiconductor shortage and the pandemic. This was explained on the lodestone which you can see in the launcher.

If you get an error, you do rejoin the queue at the position you were if it's in under a minute, but I agree with you the timeframe should be increased. The errors have been improved and most of them don't happen anymore (this was also explained on the lodestone).

This is just how it will be at an expansion launch, but it's only at certain hours of the day and the rest there are no queues.