Can I add video add-ons and/or add-on nodes to the OSMC skin?

Help and Support
2

Yes

I have
Movies
-Children
-Drama
-Horror
-etc
Shows
-TV
-TED
-US TV NOW
Music
-Classic
-Musicals
-Pandora
Maint.
-MyOSMC
-Programs
-Settings
-ETC

Once you are happy, I suggest using the Backup add-on to save everything.