mebejoe I think this was a typo, the correct extension should be ".funscript". To play locally, you would just have to have the script and file in the same folder with the same name, and run in the SLR app. Should work.
More streaming files with interactive support are coming soon, but we don't have an exact timeline at the moment.
For actually creating scripts, there does seem to be a learning curve and it does seem pretty complex. The Realtouchscripts site is probably the best place to start if you're interested in the subject. The main site has a tutorial and the community is quite active.