Castle siege

Now dear Ignis, if you can refresh my mind please.A while ago when clannabis had castle and all wards, you said it is forbiden to take another castle with our alt clans and never ever interfere with the mains from clannabis in taking those castles.
I regged with my alt clan to Dion wich is kept by an alt clan of AS and pmed keinz i will come ONLY for fame.Made party with all my buffers(wich are members of DeathSquad clan) and EvaqueeN and summoned them all next to dion siege zone.I had 30 more minutes until our castle started so i brought the ET here and rebuff fresh when i had to.In the moment that i summoned them, outside siege zone, Gallia(alt clan members) started to PK my boxes wich were regged, then i told him to stop because i came for fame and agroed him so i could buff myself.That is when keinz came and started to hit me (member of AS) not registered and after i killed him he asked for Nicoll aswell,dunno if is the same person or not.
Now my question is, why was i pked and why AS came with mains to protect a castle ruled by an alt clan?
2.If i equip 1 character of my own clan and take a castle wich is taken by an alt clan aswell i.e Dion will AS be allowed to come protect it again like they did now?
Try to remember that Sekai almost jailed us for helping take a castle with an alt clan and it said was "against the rules":, now that thank god Sekai is gone, those rules are the same?for clannabis one set of rules and for others another set?