Free pass

would it be useful to buy rakuraku goko free pass if i were to visit

Morning
wind cave & Ice cave
Lake matsuko (if possible)

Afternoon
lake kawaguchiko
Music forest
Ropeway (if possible)

Next day
Morning
to gotemba then to yeti snow town.

Would it be better to buy Rakuraku Goko Free or retro bus pass for 2 day ?

The retro buses are most convenient to access most of the sights in your list (except Lake Matsuko, which I assume to be a misspelling of Lake Motosuko). But I doubt you have enough time for Lake Motosuko, anyway.

Therefore, I would recommend to use a pass for the retro buses rather than the Rakuraku Goko Free, which does not cover the retro buses.

thanks uji,

will it be a waste to miss Lake Motosuko (even tho i have visit lake kawaguchiko) ?

does the retro bus pass cover to gotemba road ?

will it be a waste to miss Lake Motosuko (even tho i have visit lake kawaguchiko) ?

No, not at all. There is virtually nothing to see around the lake.

does the retro bus pass cover to gotemba road ?

No, the pass does not cover the bus between Kawaguchiko and Gotemba.

Oh thanks after I finish with both cave is there anywhere I should go before I go back to kawaguchiko area?

After reaching kawaguchiko I will be heading to music forest. Is ropeway interesting or where should I go ?

after I finish with both cave is there anywhere I should go before I go back to kawaguchiko area?

Please study the route and timetable well. I think you have already a busy program and would be surprised if you could fit in more.

After reaching kawaguchiko I will be heading to music forest. Is ropeway interesting or where should I go ?

It depends on the person. japan-guide.com users give it a 79 out of 100, which is neither great nor bad:
http://www.japan-guide.com/e/e6900.html

I recommend to decide based on what seems most interesting to you personally.