1. If you win and get a judgment for a cash amount, you are entitled to interest on this at court rates, but only if you claim it.
2. You are looking for your costs - it is likely you would have to call expert evidence of your injury, etc.
3. A catch-all allowing the judge to make other orders, and covers you if you got something else wrong. If you fail to put it in, the judge can only decide on what you claimed, and if something extra came out in the course of the proceedings, it would be a lost opportunity.
btw on the "Specials", make sure you have receipts in case they are contested.
As you can see, it's starting to get complicated, and that's even before prodeedings are intitiated. Once they commence you will have to deal with Defences and maybe even Counterclaims, Discovery, Inspection, Interrogatories, there may need to be a third party involved, and there are specific procedures for all of these. There are timetables for all of these and the defendant is entitled to have the case thrown out if you fail to do as required. You can re-enter, but this could leave you foul of the Statute of Limitations. You may find yourself in court innumerate times for motions for this and that. The other side will have legal experts who know their way around the system, and will use every opportunity to frustrate your claim. Even when you get to court, the judge will probably adjourn and strongly recommend to you to get legal advice, because of the implications involved (you may be facing a huge bill if you lose). When the hearing finally gets going, you are up against trained experts whose job is to pick apart the evidence you tender to the court, and cast doubt on it. You may even fail to give the necessary evidence to sustain your claim (e.g. failing to establish there was a contract in a contract case), and your case is thrown out. Then, after all that, even if you win, you are faced with the issues of enforcing the judgment if the defendant fails to pay up.
As you can see, it gets very complicated. If you believe you have a good claim, you really should get representation at this point. getting through PIAB was the easy part. Court is a different kettle of fish.