Sorry to revive a 4 year old thread, but there's very little info out there on this issue so I figured I'd update it here in case anyone searches. MS did remove the GUI to merge/rename/delete networks in 8 and it's not back in 10 so I figured it was time to track it down.
Can't help on the network map, but managing network locations can still be done via the registry. Standard disclaimers apply.
"ProfileName"="<network name you see in Network and Sharing Center>"
Or delete the entire key to remove that network profile (equiv of the old "Delete" button)
Merging is slightly more complicated but still quite do-able. First, get the GUID of the Profile you want to merge TO above, then look at the network signatures in
Each of the network signatures will have a value called ProfileGuid, paste the GUID that you found above into ProfileGuid for each signature that you want to merge into the Profile above. There are some descriptive fields that might help you figure out which is which, such as MAC of your router, Description (which appears to be the name of the network but is not updated if you change that in the above Profiles key), etc.