Hi: The download and reinstall vs just replacing the out of date files is a personal preference. The reinstall makes a connection to the mothership, then you need your license number etc. Up to you. And yes to the way to use DMXZone uninstall option. A comprehensive thread is here which links to a P7 tutorial as well as how to reinstall and steps involved.
As far as recommending a pro, we are all hoping that this will be sorted out sooner than later. In the meantime, appeal to the list here and see if anyone would be willing to look into it deeper with you and pay that person accordingly. Perhaps start a fresh thread with a title that will get attention with an offer to pay.