What is the reputation of the inspectors in your area? tough, easy, fair? You should be able to find out at your local coffee shop or lumber yard.
Did you do all the work yourself? How much work did you do? (If you hired licensed pro's they should have known to pull permits.)
Now, if you go to the Building Inspector and explain to him/her that you got carried away and before you knew it you were done and you forgot to get a permit, you may have to just pull the permit and have the work inspected. Bring plans with you so he/she will have an idea of what is behind the drywall.
Homeowners can do wirering and plumbing on their own homes in every place that I know of but, it still has to be inspected.
The odds that you will have to remove drywall depends mainly on you. If you can demonstrate that you have the knowledge required to do the work, you probably won't have to.
Again, this also depends on the inspector. You will certainly catch him/her off guard by coming in. And because of your respect for the inspector,(NEVER ARGUE, it's a "no win" situation) he/she may perform a simple occupancy inspection and be done with it.
Your inspector will probably be looking for the basics depending on what Building & Life Safety Codes your community has adopted. Smoke detectors, proper egresses, GFI recepticles where needed ect.. Your inspector will have test equipment to test your wirering.
As far as fines go, don't mention them, they may not either because you came in. Fines vary and are limited depending on what you community has adopted. Some towns double or triple the permit fee some have a flat rate and some do a combination of both. Again, DON'T mention it.
The basic thing to remember is that, "permits are cheap".
Good Luck and sorry I ran on, Jason
Ps.. If you need any assistance, please send an e-mail to my address, firstname.lastname@example.org