For Show Help, I could include a separate library to pop up a help dialog with the correct page, I already have it implemented in my other plugins. But if you wish to pop up your own dialog, or just launch a browser with the link, you can add the ID of the page to the end of the index.html?id=SECTIONID
So something like this: https://help.plugins4d.com/?id=1026
You can get the id for a page by right clicking on the section and choosing "Copy ID To Clipboard".
I will add in your feature requests to my list.
OSX will be coming later on. At the moment I am only support R20 since its a free plugin, so don't have the time/resources to put into it.