Yes to the last one. Every time I try to self-maintain various
patched versions of any particular package then that need and
situation deteriorates into a disaster over time but that's my
problem, not courier-mta or this lists.
For the better half of last year I had to maintain my own fork of a Linux
device driver, due to some bickering between the driver's official
maintainer and Linus. It wasn't pretty, I hated having to rebuild the
kernel each time Red Hat released an errata, but it wasn't the end of the
world either. I survived. And eventually the right set of patches
made it into the Linus tree. The world survived.
So we can expect that some day Courier will have the config option to