I have a 50 army stack, about 35 10 5 against a similar french stack, maybe a few more cavalry and i'm defending in the alps yet when france attacks, My morale drops to about 50%. What am i missing out on here. I'm pretty sure i should be winning the battles easily.
The French have higher base morale than you do. Until the fight starts your morale bar shows as full because it is at its maximum level. When the fighting starts both morale bar maximum is set to the level of the better army, making it look like the worse army's morale plummeted. It didn't, it just starts at a lower value.
i.e. pre-fight you are at 3.0/3.0 morale-bar looks full, you start a fight with a French army that is 5.0/5.0 and your bar will change to 60% full as you are now 3.0/5.0
how do i diplomatically annex someone?
diplomacy action in the "dynastic actions" category, it requires they be your vassal, be at peace, and have 190 or better relations with you to start the process.
Can the player call allies into a war someone else started? I haven't been able to find this option so I assumed you couldn't, but I just declared war on Austria, who was allied to GB, and GB called in Portugal and Spain, who were not allied to Austria. Can you only do that if you are the war leader? What determines if you become the war leader in this game? Whenever my tiny one province allies call me into their wars they usually stay the leader so it's obviously not pure military strength.
If you are called in on the defending side of a war you may take leadership in the war, which allows you to call in your allies. If you are called in by the attacker or are not made war leader then only your vassals will be called into the war. The attacking war leader will not change, only the defending side can change leader. Leadership is determined by some combination of strength, prestige, and the devs know what else and is sometimes difficult to figure out ahead of time.
If you aren't taking over as leader when called by an OPM it is probably because they started the war.
As Portugal, I attacked Morocco with Tangiers as the wargoal. Castille was my ally and got to the province first, now they are the ones that captured it, and I can't ask for it in a peace offer. Is there anything I can do?
Let Morocco or rebels take control of the province then recapture it or hope Castille makes a separate peace without taking the province in the peace deal.