Whatsapp workaround? What I have:
- I don't want to install Whatsapp on my phone because I don't want it to access my personal data.
- There's an organisation that requires me to use Whatsapp to communicate with them.
- These two statements are mutually exclusive....

What I want:
- Is there any way for me to use Whatsapp without installing it on my phone? (I already have a Whatsapp user account.)
- Alternatively, is there a way to install and use Whatsapp without giving it access to all my data? (Contacts, calendar, camera, photos, etc etc.) I use Android 7.1.2 because there's no newer ROM for my phone.

I realize this might be offensive to some users ("use it or don't!") but please look past that. I'm trying to satisfy competing demands here.

Update:  


I had another go at this. Installed the app again, did not give contacts permissions (or any other), and the app starts okay (on iOS it flatly refuses to start, so at least this is better on Android). 
I cannot create a new message though. When I touch the "new message" button, I get a popup to share my contacts. No! This is not going to happen.
It won't let me just type in a phone number and send to that user. (This is allowed in Signal, for instance.)
You can disable the permission given to WhatsApp from setting --> Apps and notification --> App info --> Whatsapp --> Permissions and then turn off the permissions which you don't want to share. Whatsapp needs a valid sim card to run which can be used on phone or desktop only. Hence, you can run Whatsapp on desktop having a sim card option.