Not sure I can answer your question in full but no-one else has chipped in so here goes.

I think you mean a Humax Freesat. I use one of the older Humax HDR units with a BC6 26 and have had the TV's internal PUC updated. It works perfectly for most normal operations (but there are a couple of commands you cannot make via the Beo4 controller (inlcuding deleting a recording). 

The BC6 26 does not have an HDMI (has a DVI input) but I connect the Humax Freesat via Scart because the connector is more elegantly positioned - no idea why B&O decided to put the DVI connector to one side of the rear panel. I don't think you can really see much quality difference on a 26-inch panel.

Not sure if B&O has a PUC command update for the later Humax boxes. You'd have to check that with a deale. Warning to you, though, that while some of the other Humax command sets already  installed on my TV did sort of work I was not able to get 99% perfect operation until I had the specific HDR set installed by B&O. Humax seem to use different codes across their product line.

Hope that's of some help