Title searches generally take about two weeks or so and a little time to be "read."
Yes, you will have to pay the amount due on your mortgage up until closing day. This kind of thing (delays) happen all the time and if you are looking to point fingers, there is no specific person you can point at.
Abstracts depend on a lot of varying factors. Did you have existing abstract, or did they have to recreate it? Were there any title issues w/past owners? Were there lot line discrepencies, or encroachments? etc, etc.
Closing dates are target dates, you seem to be closing within a reasonable amount of time. Also, closings need to be coordinated with the buyer, their attorney, your attorney and sometimes a bank attorney.
Good luck and I hope all goes without a hitch tomorrow.
Remax Realty Group