Hi Ben,
Not sure if you have already gone down this path, but have you looked into using connectivity rules within a geometric network?
Connectivity Rules in the Geometric Network should allow you to make these types of connections. By default, it would have to create one type per line type (ie a Main needs to be created with Endpoint), but you could design it so a Main can only have an Endpoint or Storm Drain.
If the point you make isn't one of those, it wouldn't connect to the network. You could then run a trace to find disconnected features and delete them all so you don't have finger fudges or such hanging around.
There are also a suite of tools designed specifically for editing these networks so if you need to move or add features such as storm drains or manholes, you can do it with very little hassle.
What Are Geometric Networks:
http://desktop.arcgis.com/en/arcmap/latest/manage-data/geometric-networks/what-are-geometric-network...
About Geometric Network Connectivity Rules:
http://desktop.arcgis.com/en/arcmap/latest/manage-data/geometric-networks/geometric-network-connecti...
Water Geometric Network Editing and Analysis:
https://solutions.arcgis.com/utilities/water/help/network-editing/
Cheers,
Andy
Andy Shoemaker