Nah, take the syrup down to the caramel stage like you would make for a flan. Set the bottem of the pan into cold water for a second to stop from cooking. Then take your apple wedges, blot them dry with a towel, and dip them into the hot caramel. You can do this with a fork or you can skewer the apple segments on skewer. If you dip them with the skewer you can hang them over the edge of your table, and the excess caramel will drip down and form a long spike. You can use this a nice garnish to add height.
Here are a couple of pictures from Bo Fribergs website, that show the technique with hazelnuts and little cream puffs...
If the caramel isn't too hot, you should be able to get a fairly substantial layer of caramel that will resist the moisture from the apple. In the past, I have always used granny smith or golden delcious apples with great success. I think you could get even better results from IQF apple segments that have been thawed out, as they would have less moisture then fresh.
I bet you could poach the apple segments lightly in a heavy syrup to set the color and keep em dry. The only hitch would be keeping them intact in the caramel. If you use a fork, you should be ok.
As far as using raw apples, I think you are pretty much FUBAR, unless you keep replacing them. On a side note, the pastry girl at this spanish place I used to work at, did an apple tart that had Idziabel cheese on top. I think it was just pate brisee, apples, a little sugar, a little lemon, a little butter, and the cheese. I'm not sure that she used any spices in it. Gotta go look for my notes... Good luck with your platter travis!