Awesome post. We share some similar views!
With your suspension, if you could go back and do it again, would you have done anything differently? My 2011 E91 ZSP is at 50K. When the suspension needs to be refreshed, I am planning to be rather thorough.
Also, as far as replacements go, why not pick up a 2013 128i 6MT ZMT for the next 250K miles? It will be 20% E30 (in terms of size) and 80% E90. I get the feeling that the car's going to be the end of an era...