I don't know TeamViewer. My worry is that, however good their security, you are open to unknown attackers.
Do you ever switch off the modem/router on the ADSL you want to connect to? Has the IP address ever changed? My Pipex contract was "dynamic" IP, but it never changed in the years I was with them. My UKFSN one is static anyway, so the issue doesn't arise.
You may find that you can get away happily using a conventional VPN - which gives you all the flexibility you want to give it.