A: No, you cannot, every individual who handles the data set needs to sign an individual NDA. After all, the NDA is about not passign on the data set.
A: Yes, that is the SIGMathLing is all about. We will gladly supply a repository at http://gl.kwarc.info where you can upload your data set via
git lfs. All you have to do is to supply us with a markdown-encoded data set page, such as this one and a link text for the resources page. We will do our best to make this data set persistant for the forseeable future.
A: Even though SIGMathLing was established to allow sharing data sets that cannot be made public, we encourage public licensing of data sets. This is by far preferable for open research. Apart from access restrictions, we treat public data sets like restricted ones.