Hi Stefan,
sounds good. The template tag names were growing evolutionary, and there was no special "go through" to normalize them. So, if you can collect a list, publish, then we and other users can verify it, and then I would do the change.
There is a problem possible that existing templates would work wrong, but maybe, if name would not overlap, we can leave both version.
Also I had idea some when before to provide short aliases for tag names, something like w for current word etc. I have seen that somewhere.
But I would not do such change on 1.4x branch. Better on 1.50 as a major update, plus this can be combined with some other extensions I planned for templates as another texmate like style for tags etc (${}) to make easier to migrate snippets from other editors.
And about suggested environment variables, they are not hardcoded, but generated from currently registered, so it is complex to remove something, but probably some can be explicitly moved to main sub menu.
Best regards,
Alex