Wise words my friend Ok, some news : actually I was working on the Free Demo -> IAP -> full game stuff, which forced me to use a whole different Resource management from how I built the engine around (forced me to use Unity asset bundles, for connaisseurs). But in the end it was more hassle than anything else, with yet additional work to do (so more wait for you) on top of some bugs from Unity's asset bundle part. Long story short : I decided to scrap the IAP scheme, and go the good old Lite / Full split. So I'll send it to Apple under the next few days.
Totally, I'm just finishing to follow Apple's procedure and its 36276328728 things to do before submission (it's quite insane, really). I'll send the app either in a few hours, either tomorrow after dayjob