trade denial - why??

[ViterboKnight]

Something that's happening in my game.
Ok, it's a mod, but diplomacy should work as in standard BTS.
I'm having a deal with a portuguese leader, and several things sound odd.

1- Adopt Caste System. He says "That would go against everything we stand for!". But his favourite civic is Hereditary Rule!
2- Trade clams, cows, fish, rice. He says "You must be joking", but no corporation has been found yet!
3- I try to offer my iron, horses, ivory. He says "We would have nothing to gain.". WHY, I wonder????
4- I can't see any copper, iron, horses from his in the resources list, even if he HAS those resources (I can see iron and horses in the map, where his cities are, and the tiles are improved and linked).

Maybe there are other explainations apart what I wrote in each point.
Can anyone try to explain that?

 

[Gurra09]

1. If a leader uses its favorite civic he/she won't change any civics at all.

4. A resource has to be connected to the capital (I think) to be able to trade.


Gurra09

 

[Refar]

He has nothing to gain because he already has these ressources. They dont show up in the trade screen, because he won't sell them (having one instance of each)

And he does not want to sell you clams, cows, fish - perhaps you already have these ?