Site replication

Mark, my business model calls for running multiple independent regional directories (identically looking & features) on a multisite install …
– the “plan” was to setup a master-template and then clone regional sites as needed (+/- 30).
– Used NS Cloner and tested on 7.1.4 … worked perfectly. Cloned sites with all settings, menus, categories, everything … !
– then I fell in love with the new Responsive theme and decided to build it on that …
– just ran my first clone-test with the Responsive 3.7 … TRAINSMASH!

Almost none of the settings cloned except for menus and my own defined CSS from what I could see. Images, home-page layout, etc. all is missing and trying to “set it up” throws php errors … which I have no clue how to read.

Knowing the “structural” differences between 7.1.4 and 3.7 (as the coder) do you have any immediate thoughts or steps I can try?
I know this is a bit of a “how long is a piece of string” question, so tell me to go jump if needed, but I thought I’d quickly ask before reverting back to 7.1.4