I am somewhat confused about the summons; initially it was stated that a Summoner can have at most four summons, however on the 'Summons' section of the CS there are summons labelled from one to five; at least I think that's what it means. Also each summon seems to have different numbers of possible abilities with the first and fifth summon being lowest and the fourth summon being highest, does that mean that the first summon should be significantly weaker than, say, the fourth summon?

Since there were mentions of what this role play was based on, I'm curious; I understand they don't lug around all their summons everywhere, but when summoning is it just a chanting of incantation or requires extra things such as a certain container or similar to release them, or their marks somehow play into this? 

Speaking of marks, does the Summoner require a separate mark per summon or does the number of marks not matter?

Where would abilities such as status effects [e.g. poisoning or sleep inducing], bindings, healing etc fit into, special or defense?