Well, different people have different styles of giving different presentations to different audiences in different venues.
When you have given a couple thousand presentations (and I mean this number literally), you know that requirements vary. That's why a customizable presenter display was a godsend, probably the biggest selling point that Keynote had for serious presenters.
You still can customize, turning features on and off, but you can't influence how a turned-on feature looks like size-wise.
("Looking over your shoulder" doesn't work in all venues, and probably would be recognized as the hallmark of an amateur presenter by most people in the audience who give a lot of presentations themselves.)
You can export from Keynote '13 (Keynote 6) to Keynote '09 (Keynote 5). Keynote '09 seems to run fine on Mavericks, by the way.
Not being able to see the pointer on the presenter display when you use it to point out something on the slideshow display is one thing that was wrong in Keynote '09 and they haven't fixed in Keynote '13.
(Now what I really want to get back is an alternative mode where I can edit the presentation on one screen and show it on the other at the same time...
Powerpoint in Windows was great for that. But that's a completely different style of presentation again.)