Maximum number a user can post and votes

I'm aware that there is voting mana and RC. Voting costs voting mana and posting costs RC. I have some questions about it.

1. Is everyone's max voting mana the same? And the same vote costs the same voting mana for everyone?
2. Does the same post costs the same RC for everyone? Does the length of posts affect the cost of RC?
3. How many votes can a user do with a fully charged voting mana roughly?

I appreciate any thoughts!