Re: nah
I kind of just think Yoda went into hiding because he was waiting for the right time to strike back. When you plan on an attack you plan out certain situations and certain tools. The same way the Sith did. They waited for just the right time to go through with an offensive attack. Yoda was waiting for the right tool(weapon)to come along so he could assure victory. Luke was that tool and when Luke emerged it just so happened that the good prevailed. Yoda was just byding his time for the perfect moment. He knew he was not the one and therefore knew he played a different role, one that would need to survive to train another. And the other would be the hero, after the hero completed his training yoda vanished and became one with the force. because he had fulfilled his own destiny.
Re: nah
Well, I like Yoda a lot (can you tell?) and this is what I think:
Yoda and some other Jedi were able to escape the Jedi Massacre. They all went to separate planets, hoping that some of them would be able to stay hidden from the Sith so they could train the Skywalker's to become Jedi to help defeat the Sith. But the only one's that managed to survive were Obi-Wan (on Tatooine) and Yoda (on Dagobah). If you say Yoda ran away scared, you'd have to say Obi-Wan did too.