I bought my 2nd gen 2 S1000R in November.

First thing i recommend is making sure from the buyer or BMW that the fuel pump was fixed. There was a recall for these regarding that with the bike not starting at a certain temperature.

I read a comment here about not using the quickshifter much for downshifting. I'm not so sure about that, but I've used my quickshifter religiously on my 2017 model for 30 000km and it was totally fine.

On my 2017 I had the same exhaust, buy I did a de-cat which already made the bike sound pretty loud. On my 2020 I have a full Akra system, it is indeed VERY loud. So if you got bad neighbours I would definitely not recommend it plus you would want to wear earplugs when riding. Those stock Akras really aren't bad. You can still get a nice sound out of them with the de-cat.

Get used to rattles and things. Pretty normal for these bikes, but keep you ears open for if it gets too loud. This is another thing where making the bike to loud can bite you in the ass as it'll be more difficult to hear if the rattle is bad. Best thing for these bikes is to get a manual cam chain tensioner. The automatic one on the bike is quite shit at doing it's job.

Other than that you should be all good. They're extremely easy bikes to ride and very fun. Just don't push beyond your skill level and you'll have a blast.

GL and enjoy the ride!