Add custom slots for most and fortify for flurry. You get the option to fortify again at level 10. Partly depends on how high you intend to get your levels in the game (and how long you want to play for) what you do next as you can't keep raising the CP levels if your level is low, and the second option gives you the choice to raise the level by 5 allowing you to add points even if your overall level doesn't allow it. That way you can make your attacks even more powerful.
There isn't a set answer to this but I'd add the slots for the level 7 option and maybe fortify some of the blow attacks at level 10 to give those a better chance of knocking out or tossing the enemy. (Varies for the characters which attack does what.) --- "What the ****? Philistines! Keep your grubby feet away from my flowers!" Metal Max Returns!
I used the books late in the game to reset,and when I picked the two extra slots, then the additional limits, and then fortified, I either got a critical bonus or a focus bonus. I assume the critical bonus applies to attacks and the focus bonus applies to life skills or magic spells. --- Hard cheese, go back to the start..... If I had a nickel for every time I saw this, I could retire.