My view is that you need to play, but I wouldn't know the first thing about officially rating a course. Given you spent 4 hours there, I'd imagine you'd have been itching to hit a few shots. I'm guessing here, but I assume you don't/didn't play because that would have given you a 'one-dimensiona'l view of the course through your own game?
So to answer.
1. I think so. My experience, as an example, is that I had previously walked Kingston Heath several times, and had caddied there in an Australian Open and found it difficult to really form an opinion on it, then I played it (and the first game I shot 100+ playing off hcp of 6) and instantly it raced up my 'personal ranking'. Having said that, walking the course as a spectator and caddying, are very different to visiting a course for the sole purpose of 'rating' it.
2. I'm not sure where I'd put RQ, but I'd have it somwhere in the Top 25 or thereabouts. As for other QLD tracks, I'd find it difficult to squeeze another one into my Top 50 to be honest, though I have never really thought about it. I'm not even certain which I'd rate as #2 in QLD, I'd probably actually lean towards Pelican as it doesn't have as many really weak holes as some of the other 'resort' layouts. For example, Brookwater 8-10 for me make it almost ineligible for consideration.