Wow, what a mix. First off, the sharks will get too big for that tank, they will need a new home. Neons are the natural food for angels, don't be surprised if they start to disappear as the angel gets larger. The sharks will easily eat them as they get larger.
The shrimp may get eaten by the angel, almost certainly will by the sharks. Angels & bettas don't get along too well, you may be able to pull that off due to the tank size if you aquascape correctly. The tiger barbs need to be kept in larger groups if you don't want them to get nippy with other fish.
If yu rehome the sharks you are already pretty well stocked. I would consider rehoming the sharks, and a second tank for the smaller tankmates. A 20 would work well for the neons, guppys, and shrimp. Once you do that you can consider adding more fish to the larger tank. First thing I would add would be a few more tiger barbs, this will help keep down any nipping.