Nah, you keep the spells as they are now and just utilize Guild marks as a means to obtain different abilities and traits. Though I am a tad concerned if the rumor about removing the action cost to set skills is true cause then that just means they have no plans of actually expanding on the Guild mark system like they should.
The way I see things is with the action cost limit you will end up having to choose what you want to use, however if they remove it then they'll just get one step closer to just being any old mmo clone. In a game that was represented as a means of playing how you choose if they do decide to take this path they are basically killing the tiny fragment of playability customization the game had to begin with.
I honestly don't see what's so hard about just adding a wide range of obtaining abilities, the devs keeping talking about how they need to make gear for dungeon rewards but why does gear always have to be the reward. They could easily add special Rare/EX items that can be exchanged along with guild marks to obtain unique abilities and traits for your class and actually develop a wide range of challenges to obtain them by.
Basically the scrolls could be obtained in dungeons, through Guild marks, through settlement reputation and maybe even from the beastmen. I just hate that there's a chance they are going to get rid of action cost since to me that's the most appealing thing I see with the game. I see action points and I think after a yr or two we'll have so many abilities and traits to work with it'll be hard to find two people that are actually the same. But in the end it sounds like we'll just all end up being the same with maybe 1 slight variation that doesn't really make us any different then the person next to us.
But ya getting back to the topic at hand basically keep auto-learning the same as it is now and when abilities are added later on have them be rewards from dungeons, chest, secrets, quest, settlements and such. Granted IO ddin't want to be this kind of guy but this would seriouslly be a deal breaker for me if they remove the point limit cost and instead add rank restriction and possibly worse an even firmer class restriction for a majority of abilities where they would just be better off saying, ya sorry just like how we said leves aren't a major part of the game, well customizing your class to your play style is no longer a means of customization either, sorry!