Tokyo-Kawaguchiko-Gotemba: transport

Hi, really sorry for asking this again but I'd really appreciate your input on this matter.

I'm planning to make a daytrip out of Tokyo to Kawaguchiko (morning Fuji-san view) & Gotemba (afternoon shopping). The catch is, I'm taking quite a large group (~10ppl) & most of us are Japan newbies.
Would you have any suggestions on the transportation & time we spend at each place - would we be able to make it back to Tokyo for a little bit of a walk around town? (we a very short time in Tokyo)

We have a JR Pass for the week & really wish we can make the best use of it but I've seen from some posts that to cover both Kawaguchiko & Gotemba might be better to go by bus? Is this the Fujikyu bus? Does it take us from Tokyo as well? Or is this only for the Fuji area?
Please kindly suggest what you feel is the best transportation option! Truly appreciate it!

Transportation to Kawaguchiko is explained on the following page:
http://www.japan-guide.com/e/e6905.html

I recommend to take the JR limited express from Shinjuku to Otsuki (covered) and the Fujikyu train to Kawaguchiko (not covered). The earliest connection gets you there around 9:10. For an earlier arrival you could take local trains from Tokyo to Otsuki and be at Kawaguchiko by 7:45:
http://www.jorudan.co.jp/english/norikae/

The first direct bus from Shinjuku (not covered) gets you to Kawaguchiko shortly before 9am.

From Kawaguchiko to Gotemba, there are Fujikyu buses, which are not covered by the Japan Rail Pass).

And the return from Gotemba to Tokyo is explained here:
http://www.japan-guide.com/e/e5213.html

Whether it is feasible or not in a day trip depends on what and how much you want to see and do around Kawaguchiko.