You often can, give it a try. You can install the needed Google app and see if it works. You can use Termux Widget [1] to add enable/disable links for apps so you can keep them around in a disabled state, to be enabled and disabled on demand. Create a directory named .shortcuts in your Termux home directory, any script placed there will be available through the Termux widget. Take Google Maps, an often demanded but extremely intrusive app. If you occasionally want to use it you can add the following scripts to enable and disable it:

googlemaps-enable:

   #!/data/data/com.termux/files/usr/bin/sh
   
   exec sudo pm enable com.google.android.apps.maps
   exit 0

googlemaps-disable:

   #!/data/data/com.termux/files/usr/bin/sh
   
   exec sudo pm disable com.google.android.apps.maps
   exit 0

Yes, you need root (and sudo) to do this.

[1] https://wiki.termux.com/wiki/Termux:Widget

Depends on what the app needs, but microG seems to help a lot. But the issue with the GSF is that you can't just use it when needed, it's either nothing or everything. Additionally, modifying the firmware to install microG can lead to Safety Net failing, which may also lead to some other apps failing. I use Android without GSF & microG and it's fine for my needs, but that really depends on what types of apps you use.