Regarding those 1638 errors, that's something iZotope should fix. They are probably building new install packages using an old template that's been around since Ozone 1. Devs are often guilty of that, including yours truly. It's partly laziness, but mostly it's because once you have a process that works, you don't want to re-invent it. Ironically, one includes the C++ redist package in installers to
avoid problems!
Although uninstalling the redist, as suggested to rickbail by iZotope, will avoid the error messages it shouldn't be necessary. My advice would be to just ignore the error messages. If you're on Windows 10 (and probably 7 and 8, too) the plugin will work fine.