iPhone app - slight final touches & improvements

Hi, I have an app which is pretty much all ready, but I have a few small things which need doing. The first is that I want it to send Push Notifications to other users when certain actions are made by a user. So when a user sets something up, it will send the other user a Push Notification which they can press, and it takes them to it in the app. The other thing is that it is telling me the database won't allow duplicate entries, but I know that it does, so it must be something in the app coding which is preventing it from doing so. I also need to make sure all the coding is good, and there are no errors. When I check the app in xCode, I get a few small error messages, but I don't know if they are important or not, as the app still works. I also need the logo to be made in 512x512 Finally, I need someone to actually submit the final working version to the app store for me. I have already set up all the meta data and screenshots etc I need this done in very quick time.