The "Bump" rule is actually a marketplace rule as it is posted in a thread in marketplace titled "marketplace rules and guidelines" so I would not think it would apply to threads in other, non-marketplace sections.
No. It might have been a marketplace only rule in the past, but this applies to all section without exception.
Do you have a thread or a post that clarifies this rule somewhere? The only place I have ever seen this rule posted is in the above referenced thread. Even the unofficial list of official rules references that same thread (with a footnote of [2] )