Dragon force, Demon Force and God force. Plus a few other things regarding slayers

Ok I have two major questions.

1. Are we limited to how many times we can eat our element in a thread? I have been told by a member they were told this, but I want to clarify?
1b. IF we are not limited, can someone clarify how much eating our element heals us and what not and how much we can eat per turn? I feel it healing us equal to our rank for non-enemy magic would be fair and maybe equal to the rank of the spell for enemy magic (though we'd only be able to eat probably one or two higher than us).
2. How big a boost do the forces give us. I assume it give us a rank up essentially, but by how many ranks?
3. How do we enter dragon force/demon force etc? I know its by eating a lot generally, but how do we know?

You can keep consuming until you reach your Force. How much you need to consume depends on your Rank. Usually it is 2 elemental sources equal to your own rank or more. If you're an A rank mage, 2 A Rank elemental attacks or 1 S Rank attack is sufficient to activate your Force.

Lower ranked elemental sources will rejuvinate you, but it won't heal severe wounds. It will just give you energy and stamina back to keep going.

Force usually should only last for 5 posts and can only be activated once per thread. After a Force is activated, you should become exhausted.

It boosts your physical capabilities enormously, enough to tag along with someone of 1 Rank higher than you. Physically, not magically.
Magically it brings the power level of your spells to the max of its rank, capable of overpowering other spells of the same rank and lower, but not spells of a rank higher.