I have a hosting reseller account. I have about a dozen

I have a hosting reseller account.
I have about a dozen clients websites and growing.
I create a cPanel/FTP account for them, and do fresh WordPress installs for each account. I do not use MultiSite, so far I am scared of MultiSite as I have no experience with it.

I thought ProSites might help with this, so I wanted to ask a question from my dashboard. But I had to install ProSites before I could ask (using WPMU Dev dashboard). Then I realised its for multisite only.

QUESTION 1
How to remove ProSites?
It says in the WPMU Dev dashboard that's it's installed but I can't see it in my normal plugins folder.

QUESTION 2
I want to track when all my hosting accounts were created, and when their annual hosting bill is due. Maybe I should just do this on a spreadsheet?

If ProSites isn't for this purpose, can you suggest another way to do this?

Thank you