This is not 100% related to this topic but this is as good a place as any to ask this:
For abilities to take effect, do I need to put them in a slot? Even non-combat abilities such as Delusion? If I don't put Delusion in a slot, will I not get the extra dialogue options that you get from upgrading Delusion? Or do you always get the extra dialogue options even if you don't put Delusion in a slot?
You have to slot them to get their effects, yea. Right now, I just reslot delusion anytime I end up in a populated area.
Personally, I'm hoping that with redkit, we'll be able to tweak the system so any ability you place points in will give you at least some of it's effects. I've been making notes during my playthrough of things I want to mess around with, and with some of the bumps in monster strength and overall difficulty, having unslotted abilities give 50 % of their listed value while unslotted, and treating slotted abilities as specializations you choose to focus on, and gain the full benefit of, would work wonders with what I'm planning.
EIDT: That, and I just hate the idea of abilities I've trained having zero benefit. If I've taken the time to fully master swordplay, or the use of Signs, then damnit all, I want the benefits of that training!
Even if it is less than the full value of a slotted ability.
Here's to hoping tools will become available that will let me do something along these lines. I doubt it, but I remain hopeful.