Way to Kawaguchigo

I have some questions about the way to Kawaguchigo are below
1. If I buy Fuji Hagone pass and don't use JR rail pass I have to get off at Shinjugu station and then take the Fujikyu Highway Bus to there, righ?
2. If I use JR rail pass I am able to take the train directly to kawaguchigo station, right?
3. I get some information of other plan to get off at Otsuki Station and take fujikyuko line to there, is it right?

If in 3 ways can go to kawaguchigo, so which one is the best way for budget and time?

If I buy Fuji Hagone pass and don't use JR rail pass I have to get off at Shinjugu station and then take the Fujikyu Highway Bus to there, righ?

Yes, the pass is valid from Shinjuku, from where you can take either the Fujikyu bus to Kawaguchiko or the Odakyu train to Hakone. You can travel the loop (Tokyo - Kawaguchiko - Hakone - Tokyo) in either direction.

If I use JR rail pass I am able to take the train directly to kawaguchigo station, right?

Most connections require a transfer of trains at Otsuki Station. Furthermore, the Japan Rail Pass is not valid on the train between Otsuki and Kawaguchiko.