Even though the original post was written back in July, I keep it updated with relevant changes. I usually have some tweak to it weekly if not more. A fair amount has changed in the interim, and more is probably coming. What this means is that the OP, while oldest, has the most up-to-date information on FP+ and should be considered correct before any of the conversational posts that occur after it (the rest of the thread).
1. Correct on all counts.
2. No, sorry. Onsite guests aren't privy to all available info either though.
3. I think one at a time. I would assume a nearby iPad-armed CM could ease this process.
4. I will only say that prebooking is likely to come for offsiters as well and that the current system setup is temporary. I think there will always be some kind of incentive for guests to choose onsite.
I read your original message and have looked at SOME following, but the first few pages seemed to be people agreeing or disagreeing with your rating of the rides, so I sort of plowed through those as personally I might rate rides totally different - there are 4 of us in my family and at each park we would all have a different 1, 2, 3 so.....that's personal preference and so I skipped a lot there and tried to find other snippets .
Just the one thing re staying ON SITE, I do think that's a little unfair, personally we choose NOT to stay on site, much as I love all things Disney, we like that when we go back to our hotel it's not. We like the choice, we never drive and so the location of hotel is important to us that it's flexible for us to get easily to all of the parks - disney, seaworld, Busch, universal, and also the shopping outlets and a variety of shops and eating places. That's our choice, and so people might say "well if you don't get the perks then that's your own fault for not staying in disney property" but what about people who can't afford to stay on site? Some people may have to choose a non disney property.