They haven’t said exactly when groovy support will go away. Your other question really belongs in the developer section of the forum, but the answer is, there’s an entirely new developer platform being created, and that should meet the needs of many power users.
See, for example, this recent discussion:
Need help in understanding Smartthings API
As to whether your hub will meet your needs once the transition is complete, I can’t say. There are now more devices and a better rules creator in the new app, but it’s not an exact duplicate of the previous features. So I’m not sure what your expectations were, but again, this discussion probably goes in the developer section of the forum.
Or start your own thread in projects laying out just what you’re looking for and people should be able to help you dissect whether or not you’ll be able to get that from smartthings.