Intrigued by but brand new to arcREST. However we are looking at changing our map service structure to essentially have most of our production SDE database feature classes published out as single-layer map services. This would be a lot of really tedious publishing. ArcREST looks like it may be able to do this, but all I've found searching around is how to work with services already published. Is this possible, or a deadend?
ArcREST is a module that works with ArcGIS Online hosted services. If you want to automate a way to publish your SDE feature classes to ArcMap, take a look at the following link:
The first code sample should be what you're looking for. What you would need to add to this is adding your feature class to ArcMap, and then saving this as an MXD.
Yes, ArcRest can definitely do what you are looking for. You need to do it in two operations. First you need to add the item, second, call publish on that item. When I craft a script in ArcREST, I used fiddler and complete the operations using ArcGIS.com. I watch the traffic and reproduce that in python.