Had interesting wow moment couple days ago.

My wife had some issues with her WiFi network connections while I was unavailable. So, she called vodafone and asked for assistance. Vodafone employee was able to remotely reset router settings to default and change password per her request.

Technically, it makes sense that Vodafone had their "enough" with unexperienced users and included backdoor for their convenience, but I'm concerned because I was treating network as private and there are number of unencrypted channels SMB/NFS/HTTP control panels, etc. Also all router settings with port-forwarding, mac white lists, and other custom settings were completely wiped, which is annoying.

So my question is:

 

1. What vodafone employees can do remotely in addition to hard reset and change password? Can they read any settings or only can set some of them?
2. Should I install own Wi-Fi router instead of this one or I can somehow limit remote access to it without replacement?