If you have at least some experience and are taking a bunch of newbies, I would suggest making it at least a semi-planned event. It may not be right to schedule time together all the time, but do enough (most) stuff together to give them the benefit of your experience.
One thing that may be difficult is gathering input from people who are overwhelmed by the amount of stuff there is to offer opinions on (if you are trying to garner opinions), I wrote the following in another thread but I think it is quite appropriate here:
"I can have a similar problem with my family offering opinions on whether they like or don't like something (mostly because they're kids so they don't always know what they want LOL). I get around it with the Disney Dinner Poll ... when I first start planning a trip, I work out the parameters I want input on and then I take a poll on one question every day at dinner. It's much easier to express an opinion by making a choice between two things than to say whether you like or dislike something. Some examples:
- If we have one sit-down meal per day which would you prefer: a) take a break in the middle of touring to eat, then go back to touring or b) eat either when we are done touring (lunch) or just starting out (dinner). If the answer is a, then I will make more early lunch and late dinner ADRs to give a break from touring, whereas if b then I make more late lunch or early dinner ADRs.
- Would you prefer to a) all stay together if not everybody wants to ride the same ride or b) try to split up and meet up again later. If a, then I don't worry so much about trying to make forked plans, if b, then I will.
I find touring style (as addressed in the above questions) to be a bigger factor in trip satisfaction even than what people want to ride and where they want to eat. But I also have poll questions asking to choose between two restaurants for example Boma and Sanaa (more expensive but opportunity to try more things for Boma vs. traditional single entree but lesser price tag with Sanaa), or same experience different cuisine (Cape May breakfast vs. Tusker House). Oddly enough, restaurants I don't want to eat in never make it to the poll. I will also poll attraction types (do you or don't you like water rides) and other random stuff."
You could start with a poll question on how much time people want to spend together.

I think it may go without saying but I ask the broader questions first; if I haven't determined that people want to take a break in the middle of the day then it makes no sense to ask about the placement of lunch / dinner in relation to that break.
As far as touring plans go, I have a subscription to touringplans.com and I love it. The thing I like about it best is not that we follow the plans to the letter while in the park (because we sure don't), but that it gives a good feeling for how much can reasonably be accomplished, and enough of an outline to our park day that we do not spend time arguing with opinionated teenagers about what we should do next. It also in your case may give you something (in the later stages of planning) to present to your tripmates as a rough guide for the day so as to make sure there's nothing obvious that they've read about or are looking forward to that has been left out of the plan. What I like about touringplans.com as opposed to one of the other websites -- and which sounds like it may apply to you -- is that I actually have enough knowledge of the parks to say with some confidence what I want on my touring plan, and so I don't like to start with other people's sheets that don't match up with what
I want to see or my planned arrival / exit times from the park.