As PPs have mentioned, the antics are simmered down at breakfast at WCC. Much more mellow in the morning. If you're hesitant to try WCC because of the antics, breakfast would be a good meal for you. It's also all you can eat if you order the skillet. We've only had dinner here which has been very good, and it's great overlooking the WL lobby while you eat. Also staying at POR means MK is the quickest park to get to, so you can fairly easily transfer over to WL.
Will you have a car? If not, Olivia's is really not that convenient. Boats are few and far between that time of morning and I think you'd have to transfer at DTD which would add to the commute. I don't know that Olivia's is worth going out of the way for - food I've read is good, but the menu is a la carte and it's one of the few dining options at OKW which means it could be busy. The Dis Unplugged podcast did a review of OKW recently and ate at Olivia's, and had negative feedback regarding the service and how slow they were to be seated.
On another note, since you'll be going to DHS that day, have you considered Cape May at BC? It's more convenient to DHS and we enjoy it. IMO, both Olivia's and WCC are pretty out of the way for a DHS day.