I had a similar problem with the key fob, affecting both keys. I purchased new casings and installed them myself, since I disapproved of the silicone covers previously applied to the original fobs. Simple remedy, and they seem as good as new today.
I have not yet encountered the seals issue; however, I suspect an imminent Haldex problem, as my vehicle intermittently switched to 2WD only, with error codes indicating a Haldex pump pressure issue. Ironically, the day I returned it to the dealer, the problem ceased, and it has not recurred over the past few hundred miles, though I am confident it will resurface eventually.
Replacing the gearbox oil is included in my list of DIY preventive maintenance jobs, along with the differentials as well.