I would go for choice 3. Something along the lines of bouncing to Stack Overflow if the question is purely about implementation. Such as:
But if the question has to do with understanding some theoretical aspect of statistics and then carrying those concepts forward into implementation using a tool, R or otherwise, then I would vote that Stats should have a home for it.
I have been tagging questions that may be too heavy on the programming as "possibly-off-topic":
This way, we can easily locate them once we come to a consensus on this issue.
Retracted- see here.
If you find a question that you think is off-topic, link it to the appropriate discussion on meta so that it may be tracked. If there is no discussion on Meta yet, consider startin one!