I hear ya about not wanting to carry a heavy camera around all the time, but the reality is that if great photos are important to you, then that's the best camera to use. You could perhaps try bringing it with you sometimes, but not every time -- risking that you don't have it with you when the best photo op happens.
Your waterproof point and shoot might be your best compromise....
I personally do not find iPhone photos to be of the kind of consistent quality that I want from our WDW photos. Going with PhotoPass is a good supplementary option as well.
I do carry a heavy, top-end dslr and usually an extra lens with me every day in the parks (only exception being water parks, then I go waterproof point and shoot...). I go with a highly unfashionable fanny pack that can fit my camera when I do need to tuck it away (on rides, for example).
If you really want a lot of very specific and expert opinions, I encourage you to re-post your question on the Photography Board here (it's pretty far down on the drop-down list of options, but it's the ideal place for great photo advice).