Well, no-one here has any more influence with Apple than you have, so you should use http://www.apple.com/feedback/ical.html to tell them.
You could set up your templates using MS Word, or similar. Then, when you are eg arranging a funeral you use the funeral template, and save it as a new file. Then when making the first iCal entry relating to the funeral include a link (attachment) to that funeral file. Subsequent entries would be made by copying and pasting the original, then changing date/time, thus preserving the link to the file.
Your 5th Sunday issue might be manageable if you could give an example.