Will I still have to change the Hotkeys.ini file in EW7 whenever I want to use different clickers? Or the different button functions in different clickers been addressed so that they will all work (like they do in PowerPoint) without having to dig around in .ini files?

You'll need to install the hotkeys file for version 7. You can get it from the following article.
https://support.easyworship.com/solution/articles/8605
Also you can use the iOS app on your iOS device without having to mess with hotkeys.