Ok so this is what I think.
1) No whilst you hit the mark by Gybing and impacting the mark, this is not part of your turn. The rule states you must now sail clear of all boats and take your penalty turn as soon as possible. Whilst taking your turn you have no rights and if you infringe another boat or boats you will need to take another turn.
so what you have explained is two seperate infringements so two penalty turns.