I would suggest you open a few bug reports on these issues so the developers can look at it. If you already have code, you can submit it there as well.
I regularly tweak things and share the fixes - but usually I find it helpful to get other people's perspectives (and in some cases, uncommitted changes) before I put time into something
The first thing I was going to fix was intermediate CA support, but then I found it is just not documented, so I've tested it and shared my findings about that on the users list.