We were put with other couples/families. For us it was about 9 people total but I think they may take more. With you having 6 guests I would think that you would have no more than 6 other guests with you on the tour...but I have no definitive knowledge of their cut offs on number of people. I do know that they "sell out" particular time slots so they clearly have a limit on what they will do for each show.
As for the tour itself, what they did was they had a driver, and then they had a guide who sat in the front row (where guests normally sit) and turned around and talked to us the entire tour, and answered questions. While we had other guests with us, it is definitely a more personal tour, though nothing like the more expensive wildlife safari tours that Disney offers. Our tour guide was a biologist and animal nutritionist so she had plenty of scoop on the care and upkeep of the animals.
It was the same path, and therefore the same length, as a regular tour. We loaded in a slightly different area but we ended up going through the same path as the regular safari.
Yes, when I booked they only had lunch times available, and we ate at 2:30. Fortunately, the lunch menu is the same as the dinner menu, so we didn't miss out on any options such as the delicious Surf & Turf. Once we booked, we basically just showed up a couple of minutes before our lunch reservation and told them we had the package. They confirmed that, and gave us lanyards to identify ourselves as package guests. We had lunch, and they had assigned us a 5:00 FOTLK show. So we strolled around for a bit and showed up at the handicap entrance to FOTLK (they were outside looking for people with lanyards). They gathered us up and escorted us to our front row seats. In our case, we were the only two in the VIP front row for the "giraffe section". One of the package guests who sat in the "warthog section" was the guy who had to demonstrate the warthog look and sound to the audience. I think if there are kids there is a decent chance that they will be asked to participate in either the animal sound demo, or in the final parade. They seem to try to make the package guests feel like VIPS. Once the show was over, they gathered us up and took us straight to the Safari where we boarded at that location near the regular boarding. There was no wait.
Overall, it is a really good package, and with Tiffins thrown in without restricting the menu choices, it was well worth it! Enjoy your trip!