1. Your vassals will convert the land to Catholicism for you. You can, of course, help with your own Chaplain if you like.
2. Give the counties to courtiers. Use the Search button set to "Realm" and look for men that are literally nobodies (no family, no claims, no land, no wife) and give them counties. If you can't find enough of those you can create courtiers out of thin air by right clicking on a city, church or non-capital castle and using the 'create vassal' option. In a county with two baronies you can then give that same baron the County as well. It is better, however, to give to courtiers because then you can avoid traits like Ambitious that will make them not like your rule.
3. As long as you didn't marry matrilineally there is no problem with your Heir gaining this land. Since you are King any lands you conquer and any vassals up to Duke will remain under your rule. If you did marry off your heir matrilineally then you need to kill him, change your succession laws to allow a different heir or wait till he ascends the throne and then divorce or bump off his wife so your dynasty continues.
4. General advice:
- Since it is early I would not give any of the new lands to your existing Dukes (a good general rule is one duchy per Duke. To see the results of not following this, pay attention to how many times the Duke of Aquitaine becomes the King of France...). They could very well end up more powerful than you in 15 years or so and cause major problems on succession.
- This is a bit gamey and what you do depends on your playstyle, Granada is a better capital than anything in Ireland. If for no other reason than it is way ahead in technology. (The Legalism of 2 will let you have a bigger demesne, for an immediate tangible benefit.) You might keep it (and the two other counties in that duchy) for yourself.
- The other coastal Duchy is a great place to create a Lord Mayor or two (or even an entire Republic with a Doge). It won't pay off until the conquest and conversion timers expire, but when it does the cash will roll in like no tomorrow. To do this grant a city to a Lowborn courtier or use create vassal on a city and then grant the County to that same person. One Doge can double your monthly income easily and with all his free cash he will build out the entire duchy for you. It won't produce as many troops as a Duchy, but money is very good, esp early in the game.
- Once you save up the money you want to Ursurp or Create the Duchies in Andalusia and consolidate your holdings to 4 dukes/doges down there (or 3 dukes plus what you keep for yourself.)
- If you want to roleplay a bit (with some beneficial side effects) you can give one of the Counties to a Bishop, making him a Prince-Bishop and creating a theocratic county. And from there you can even give that vassal an entire duchy. The advantage of having a Prince-Bishop or Prince-Archbishop is that they don't care about a lot of the things Dukes do and so are generally easier to rule. They also provide more income (but less troops) as long as they like you more than the Pope. The downside is that if they like the Pope more (or equal at 100 each) they give you NOTHING. No money. No troops.
