Problemas here, I am actually on a section of the Cadenza II where it requires Quintuplets (y'know, number |--5--| over a section of notes to be played in one beat I think?), and my program doesn't support it O_o
Neither does is support the easy tactic composers use in the scores which I keep having to spend ages on, where they write a Semibreve, and loads of quavers whilst they are supposed to be playing, NOT happening in this software... I have to split the Semibreve into 8 Quavers sometimes!
Anyway, besides that annoying thing, and that problem... one more thing to hack your brains...
Since this is more like a "word processing" program for Notation, I cannot manually draw the long: > or < over series of notes and stuff O_o I was hoping someone could fill them in for me if I don't manage, but unless you have noteworthy, I guess my efforts may be what you summarize as:
GUTTED ¬_¬
As for the mention of Finale, if you have the free version, don't even try coding it in, hell you can't even export as a midi O_o Although I'm sure you do know what your doing

And on a final note, perhaps anyone knows a great notation program capable of these complex operations, and doesn't require money or illegal action to fully utilize ^_^;;
EDIT: After reading what we are trying to accomplish, I don't think I'm even reliable enough to do this O_o For myself was enough... lol, I wouldn't be suprised if I made a mistake somewhere already, despite my great confidence I got it right :/
EDIT AGAIN: Or I won't let everyone down, lol *continues*