Hi Shakey and welcome to TM

Regarding luggage; we carry a decent sized Samsonite suitcase, with a waterproof cover. Also because the lovely Lady Budster does not know the meaning of "packing light" it usually weighs in at around 25kg. Other than putting an extra couple of psi in the rear tyres, we make no other adjustments.
Also Stanley has no high level brake light, so that has never been a concern.
Attached file shows the set up (Stanley is the dark red 4/4)