Most of these vehicles have 3 seats with a machine gun mount. I will focus on BR2 jeeps for this suggestion, but I have hopes that in the future there will be a roof mount for trucks that can provide protection for passengers like this to make it a slightly worse side grade to the APCs.
Universal Carrier was used in a similar role as the Jeep, but I refrained from putting it in the suggestion since it was already in the game, although maybe you could work it out so it could go in the rider class
The problem is, if they function as APCs then they would just be better APCs because they would be smaller and easier to hide. Unless we start to get into some sort of system where the biggest and bulkiest APCs have a faster respawn time than the tiny ones or something.
20mm Mg FF/M on Kübelwagen VW Typ 82 could be a nice event vehicle.
it was supposedly made by the Luftwaffe as a support vehicle and It is mentioned that it was used in North Africa, that is however unconfirmed.
I like all these ideas and agree with all your points.
For Universal Carrier I propose the Australian-made UC. Our Aussie one was slightly different to the standard UK one, for example ours only had a single Vickers HMG.
This would be not OP, allow for differences with the event UC and also the possibility of a proper tech tree Australian squad.
I think is going be something more than a jeep, because the class is going be reworked as stated in the road map, otherwise if was just a jeep planned it would be already be added by now to all factions