I would say to need to have the Xbox Application (XboxApp), since that will make it easier to launch games. Games that install on your computer get buried deep within folders as I've found out. Gears of War 4 for example was within a very messy folder structure. I'm not even sure if it was possible to launch the game without the app.
XboxIdentityProvider is likely needed as well. This site states its description:
The description says : "A system app that enables PC games to connect to Xbox Live."
Here is the link to redownload the identity provider. You won't be able to connect to Xbox Live if you do not have this downloaded.
You should be able to get away with not having the XboxSpeechToTextOverlay, which at the moment, appears to only be available for one game (Halo Wars 2). According to that site, this service provides:
...a speech-to-text service that also supports text-to-speech.
I assume games will work fine without this - Halo Wars 2 may be the only game impacted by it for now if anything.
The XboxGameOverlay I believe is the service that controls the feature when you press the Windows Key + G. The first result after Googling it yields this article about how to disable it. You should be fine without this, but note that taking screenshots and recordings with this service allows you to share it to Xbox Live (using the above mentioned Xbox Application). Without it, you won't be able to share your content to Xbox Live - or at least not as easily.
Reading this Microsoft Help article, if you are signed in with a local account:
Upon launching any Microsoft app, including the Store, you'll see a prompt to sign in or create a Microsoft account. The first Microsoft account you use to sign in will become the default account your device will use to sign you in across all Microsoft services.
If you are using a local account to sign in to your PC, you will need to use a Microsoft Account to use any Microsoft Applications (including the Xbox Application).
If you use a Microsoft Account as your PC login:
If you signed in to Windows 10 using your Microsoft account, that account will be linked to the user account signed in on the PC. This makes it much easier to sign in to all Microsoft apps (Skype, OneDrive, Office 365, Xbox, Groove Music, Movies & TV, and much more).