Sensei

I have been using ModularDS for about half a year. It works very well. I had zero problems. I have 15 websites connected to it. I use it for updating and database cleaning and smaller things like that. Support is super helpful but I didn't have any real issues anyway. Updates are coming steadily and the features that are being added are great. I have not used any other Wordpress management tools before, but I don't think any of them are better than Modular, from reading their list of features and Modular is still young, so I am expecting it to blow up sometime soon. It's one of the few tools that I can 100% confirm it was worth adding to my stack.

Modular is still young but gets constant updates and these updates are spot on.

I didn't really consider the alternaties because I didn't want to self host and didn't want recurring costs either and didn't absolutely need a wordpress management tool. But Modular seemed great so I just went for it. It for sure seemed convenient to have one.

Yes.

I don't know. I am the only operator.

Yes, generous limits on backup size. Not on bandwidth as far as I know.