More repeat options

I have many actions that are repeating, only a few of which fit the currently available options (i.e. daily, weekly, monthly, etc.). I’ve been able to find workarounds, but they are awkward. I would love to have the flexibility to schedule a repeating actions at any interval of days, weeks, or months that I choose, as well as on a certain day of the month (both a “date certain” and something like “the fourth Tuesday”). Even more helpful would be a feature that auto-generates a repeating action upon completion of its predecessor. (For example, an option that would read “Generate new action x days/weeks/months after completion.”) Thanks!