Dear Customer,
Thanks for writing in !
Unfortunately, it would not be possible to recover the license if the h2h file is lost before applying on the target machine.
1. The rehost operation can't be undone. But in case, you have applied the license successfully on the target machine. Then, you can again re-host the license back to the original machine.
2. No, the license can't be restored back but can be re-hosted back as mentioned in point 1.
3. There is no time limit in applying the license on target machine in case its not a time/date based license.
Please feel free to get back to us.
Thank You !