Your steering issues sound scary as hell.
I'm kind of keen to deal with stuff like valve steam seals, alternator gasket, coolant transfer pipe, etc. to get some experience, but I'm fairly sure I'm not gonna wanna do it twice. I dunno man, V8's just have a special place in my heart. I think the S65 is the only other engine I'm interested in.
It seems worth investing in learning to DIY the N62 because there are so many bargains out there with different form factors - 550i, 550i touring, 750i, X5. Heaps of really good deals because people have been quoted $4k from a dealer to fix one or few of the above issues.
Of course it's pretty easy for me to say this - having never done any of these tricky jobs!
I've done that. It helped a little bit, but I still made the habit of treating 1/4 like 0 😀