ya I mean that's basically saying you would prefer there really to be no memory system and use other mechanics for balancing,
No, I said the memory system is find, but for aspecific purpose. It's fine to limit the use of high-level spells for which you lack the proper school ability level. And it's fine to limit the overall amount of spells you can use (actually it's fine to have this general trade-off between more spells/skills and the possibility to upgrade your base characters values).
But I don't see the memory as a balancing system. It has nothing to do with preventing spell combinations, it has to do with creating a situation where your character becomes dynamic and your playstyle can change throughout the game by trying new builds.
I fail to see how limiting the player gives him a better experience here. There is nothing more dynamic in the current solution either. It's actually less dynamic and much more rigid. And DOS was a classless game for a good reason, in order to maximize possibilities, but of course with the whole structure of a classic RPG in mind. The current implementation is working exactly in the opposite direction, by giving the player less possibilities during combat. This whole "build" thing is derived from PvP-MP and it works pretty well there, for balancing reasons and for the very sake of trying out different builds. For a classless SP game with traditional RPG mechanics it doesn't. You don't need a build for dynamic gameplay or for different playstyles. On the opposite, having a bigger arsenal means that you can change strategies on the fly, without the need to reload and change your deck. Why introducing a mechanic that is inflexible and rigid when you can to the same thing better and faster without? But of course your character is kind of tied to the way your levelled him up which only makes sense in an RPG, even a classless one.
Implementing skill tree related memory will actually serve to pidgeon hole your character into a single build more often that the current mechanic. How could I ever justify using a 5 memory Aero spell when I could use a 5 memory pyro spell for 1 memory instead? I would instead just have an Aero focused mage that uses Aero spells and a pyro focused mage that uses pyro spells. (of course each mage would probably spec 2 or 3 spell trees, but you get the idea).
Of course you would and that makes only sense. Of course a master aero wizard should be better at casting aero magic than an amateur. It's pretty pointless to let your pyro wizard cast aero magic if you have an aero master in your party, so what's the point anyway? Why skilling any school if it's pretty much pointless in the end? Skilling up and becoming better in a school should give your character real benefit and a pyro master should of course be better at casting pyro magic than everybody else. DOS was never meant to be a game in which every character can do pretty much everything. And I don't think such a system would enhance the fun of playing the game, on the opposite. Much of the fun of playing a party-based game comes from finding a good combination of characters with different professions and skills. If everybody can pretty much do the same this becomes pointless. A classless system doesn't mena that everybody should be able to do everything equally good. It means that everybody can evolve into everything by climbing up the ladder in various skill and spell schools.
And their skills would be much more "set in stone" so to speak. They are of course changeable, but it will mostly be adding a utility here or there, or adding a new respective powerful spell.
That's how games with skill schools work for a good reason (see above). Actually every RPG works that way, even solo action RPGs like the Witcher. If that's not good anymore we could ditch the whole RPG system altogether. Why spending points for skill schools if that only makes you character less flexible? It's a good question, really, but if you think it through, the answer is that if you really want a completely flexbile game in which everybody can do everything you can just ditch the whole RPG thing alltogether. What you want is truly a PvP-kind of experience, with everybody having the same basis and everybody has a set amount of skills they can use in whatever combination. But sorry, I like my SP RPG campaign experience and I honestly don't think that such a PvP-derived "everything is possible" mechanics serves this well.