The kits are all the same, on a mac the library is here /Library/Arturia/Spark/Spark Library/ In theory you can just copy the folders into this location. Which I have done on occasion and has worked perfectly.
Here you'll find all the kits under Factory, kits you save will be under user. Looking through the Spark 2 kits the VDM is there, the EDM is there and the dubstep seem to be there in parts. I also have the expansion packs installed so I do have extra kits not in VDM, EDM or Dubstep. Looking through the names of the dubstep kits, although the names seem to be different, I do have these sounds and samples.
I think this is just down to how the kits were called in EDM and Dubstep. In the bank selection you can see Spark Vintage as a sub category and all the kits are listed below, this isn't the case for EDM or Dubstep, yet some kits and sounds are installed.
Certainly the names of some of the projects have changed, whether that means the kits are different, I'm not sure.
In answer to you other question, yes. It's easy just to drop your kits into the above file location and restarting your machine should bring all your kits in. Not sure of the PC location, something like C:\Program Files\Arturia I imagine
Hopefully this will help out out