What's the best way to install Trunk version for a newbie? Also, I see reference to a Fixes_2_0 that can be installed with fpcupdeluxe.
fpcupdeluxe would be the easiest way.
I would install trunk for cocoa development purposes (because the fixes some faster).
When one of the bug reports get fixed you can just update it and you have the fix. Otherwise you would need to wait.
When the fixed reach the fixes-branche you could use one of those for a more stable release.
(Sometimes trunk gets broken but usually it gets fixed right away)