I'm rather new to Anima, but I love the flexibility and options I have access to with the dominion technique system. However, a few things confuse me, and while I was able to answer some of them myself, I'd like some clarification...

First, my character's going to have a single strong yet expensive attack and a cheap defense boost as two of her techniques. I don't think I'll have enough accumulation to afford both techniques in the same turn without spending at least one turn accumulating ki, but from what I understand if I use a technique I lose all the ki I've accumulated back to my pool. Is there any way to start saving towards my attack but still use my defense, without having to go for a round accumulating without using the defense technique?

Second, I see I can make a technique that gives me both a defensive bonus and a bonus to a counterattack. However, as far as I can tell, I can also just make two different techniques, one for defense and one for counterattacking. Since doing the latter will mean not only can I defend without paying for the counterattack (either because I'm saving up ki or in case I don't get a high enough defense), but paying for both is cheaper since they can both use the cheaper primary cost, is there a reason to have both effects in the sam technique?

No, you cannot accumulate Ki for one technique while executing another. Once you spend Ki on a technique (or stop accumulating) all unused Ki is returned to your pool. You can however make your defensive technique maintainable. This makes it so that you can reactivate your technique each successive turn for a lower cost (the maintainence cost) and this cost is paid directly from your pool, without accumulating. You can accumulate Ki for a technique while maintaining another (or more than one). This however increases the MK cost of your technique as well as the initial Ki cost (it is increased by maintainence cost).

You cannot use more than one technique on the same action, unless both have the combinable advantage (this advantage is covered in Dominus Exxet, not the core rules). This increases the MK cost of both techniques. Also, as mentioned above if you want your technique to be maintainable the MK cost of said technique will rise by 10 times it's level. This price is per technique, not per effect. This means if you have more than one maintainable effect in a technique the surcharge is only paid once. If you make two maintainable techniques you have to pay the price for both of them.

Right now I'm not sure if the counter attack is part of the same action as the defense. If yes, than you could not use two different techniques on it unless the are combinable. Personally I think you can't.