Is it well optimized for ff max and come with key mapping default?

No. Genymotion is a professional Android emulator for app development, testing, and security testing, not a gaming-focused emulator, so many games may not work out of the box and optimization for FF Max is not guaranteed.

For key mapping, the docs you gave do not mention any default key mapping for games. They only show device multi-touch shortcuts like zoom and rotate in the web UI in Genymotion PaaS Overview.