Late, but if you are running this in SSIS, have you enabled logging for the package and check that? The Job logs aren't great, but if you look at SSMS...

You need XQuery to do this. You can search a series of XML documents in rows and then update then. It's not easy or pretty.

This article might help:...

Have you downloaded the Provider and installed it on the server? That is sometimes an issue.
https://www.microsoft.com/en-us/download/details.aspx?id=13255

Also, is this path the path on the server or...

I'll say that I find JSON easier to read, though once it gets complex, both of them are hard formats to work with. Haivng SQL Server work with this can...

I'd say it's slightly safer as none of the meta data for the db is removed and added back. If there were some issue, you might have an issue doing...

Anything in the error log? I wouldn't expect this to take this long, but it sounds like something might have hung. 

I'm assuming you:
created DMK in master on...

You can also look at Target Server Memory in Performance monitor to get an idea of what SQL Server thinks it needs.

Either method will work, but as Scott mentioned, there isn't a need to detach the databases anymore.

For a little break and a fool good moment: https://www.youtube.com/watch?v=ZKSWXzAnVe0

There may be different results on different versions. I get 8061 on 2014/2016 today.