How can I delete DataMngrUI (BearShare)

You're very welcome, Nocturnal
What you see in msconfig now is just an entry
The fact that you were able to delete it finally shows that it wasn't running at the time so you're ok for the time being.
Ken already answered your question about multiple AVs
So you're good to go
Thanks for the feedback
Happy New Year

-DG

Malwarebyte is not an AV scanner like ESET. You can have both on the system at the same time.
If you do a lot of surfing of unknown sites. It's a very good idea to keep Malwarebytes and run it from time to time.

At minimum once a month.