1) A pinned HQ unit can give orders only by radio but have a -1 modification when drawing cards for commands. HQ pinned can also be activated. The actions allowed are limited by the LAT limitations chart, yes. However, must be in good order to give commands by visual-verbal contact.
2) Yes, regardless of previous/original experience.
1. A pinned HQ can only do the Actions stated in pinned, none of which are commands on other units, those actions can be commanded by higher HQ/Staff if in communication , Visual / Verbal (only rally actio ), runner or via a network.
I have no idea why you think having a radio makes any difference perhaps you are confused it with the errata :-"In 4.3.1, after "be unpinned," add the following exception in parentheses, "(Exception: Pinned units can always received a Visual-Verbal Rally order.)"
In effect allows any pinned unit to be rallied that is in communication by any means,Visual / Verbal, Runner or via a Network.
2. Includes current experience , which it retains if flipped back to non FT side.