The .zip file is containing only the basic Oxwall install files (admin and base language pack) and the plugins, which are implemented in the basic install package, like events, groups etc. 'Third party' plugins files like SkaDate are not implemented in this basic Oxwall 1.8.2. language pack.
SkaDate is using Oxwall so you can use this for SkaDate, but you must be careful, because if you are already using SkaDate and you have a lot of user registration/profile questions, these questions are stored in the 'base plugin" part of the language pack. They are your own custom questions, so they can not be implemented in a language pack (this one is as clean as possible without any user questions), of course.
Because the user questions are custom, it should be a nice improvement to Oxwall to have those user questions stored in a separated language table or so and not stored in the base language table. The base language should be stay as clean possible because then it can be exchanged more easily. To seperate the user questions, may be the language prefix key for them can be "Profile" in stead of "Base" or so. I am not a programmer unfortunately and I don't know how (easy) this can be done. ;-)
Regards