Whether or not any of these are bugs and warrant their own reports, I'm not sure... but, I figured it'd at least be worth mentioning them here so that anyone who happens upon this post and wants to try using null-named variables will be aware of their pitfalls and limitations.
There are no plans to change any of these behaviours. There is far too much history and backward compatibility to consider here. The only reason % by itself was allowed to work in some contexts is either through complete chance or because some scripters requested it. I will not be making any other changes to support it in other contexts.
