Very interesting project you got going here.

I'm really intrigued by how you want to implement DnD classes and spell systems.

Last time I read a DnD book was in the early 2000's, so forgive me if my grasp on the ruleset is a bit archaic.

How do you plan to implement classes that rely on selecting spells for memorisation, wizards and clerics, and sorcerers who can freely access an albeit finite number spells that their int. and level allows?

The D:OS 2 already have a skill memory system implemented maybe that could be tweaked to cater to the 'spell selection on rest' system DnD uses for some classes.

If the source point system for D:OS 2 can be modding into several categories, basically meaning that you have several types of source points. Then you could make different pools of them, source points lvl. 0, source points lvl. 1, source points lvl. 3 and so on.

This could help implement the sorcerers spell system. Basically every time a sorcerer rest, upon completion, he will be given several pools of source points, according to his level and int. bonus. So he would be able to spend source points lvl. 0 for level 0 spells and source points lvl. 1 for level 1 spells and so forth.
This will need to be scripted in, along with a script that removes any source points available at the start of resting.

I'm really just a novice at modding/coding, so I'm kinda not able to tell if this is feasible and/or to what extend, just blabbing ideas here.

Another question, that I really does not hope will be an issue, is about copyright infringement. It would be really sad and frustrating to spent countless man hours just to be sent a cease and desist letter, from Wizards of the Coast (they own DnD now, right?).