New purchase, a few questions

[Ron07x5]

Fyi ... I recently purchased a 2007 x5 4.8l with 105,000 it had a significant drip from the transmission pan gasket. I ordered the oem pan-filter and 5liters for oem zf fluid from rmeuropean.com the fluid is expensive. I squeezed 3.75liters back in.
Transmission holds about 10 liters but you can't drain it as it sits in the torque converter and gear section of the transmission. I plan just to change the 3.75 about every 25,000 from now on. The fluid was very bown and clearly needed to be changed.

These cars have four 02 sensors that are supposed to be changed at 100k and the spark plugs at 60k of course the double air filters might go 30k. My plugs have 65k on them and the 02 sensors haven't been changed. It does seem to idle a bit rough when first started and also maybe just a little rough when warm. I plan to use a carly-bmwhat odb2 reader to look at fuel trim and consider plugs and 02 sensors but I haven't found time yet.

Haven't felt or heard a suspension issue need to inspect for it.

I tried to use bt to stream audio and seemed I could not. Could only get phone audio working via bt.

I have the known oil cooler drip. In next month's I will be doing the significant 3hour job carefully.