Hiya and welcome to the forum
The answer to two of your queries: microchipping doesnt hurt, we had a kitten done the day we picked her up, then she travelled 2 1/2 hrs by car home. she was a little sick but not much else, if anything he may just be huffy for a couple of hours.
As for the ornaments, pity you never found us before hand, all of us would advice to 'kitten' bengalproof your home, this requires plenty large platstic boxes with lids and just clear your home. As you would with small children.
Maxi has a lovely face, we hope to see more pics.
ps..as for poooooing in the bath, to be honest I would rather them poo in the bath than behind the couch....maybe his litter tray wasnt in reach when he needed to go. Its best even with an adult newbie to have the tray close to them especially near their comfort zone, when they get used to their new environment then you can move the tray to where ever it is going.
we had the litter tray in our living room for a week. Hestia and Zeus's tray is still upstairs after a fortnight, in the spare bedroom