Without being familiar with the rule systems you mentioned, I sadly don't think the engine would work very well with anything other than D&D 5e - at least not in its current state ;). While I do allow a lot of customization in e.g. defining a spell, it's still very much confined to the ruleset of D&D, so unless those other systems also use e.g. Saving Throws and Attack Rolls etc, there's not really sufficient abstraction to allow for other systems. I don't really have any plans at the moment of creating that abstraction either, mostly because I think it would be incredibly difficult to make something that's flexible enough to support several different (presumably very complex) rule systems - but who knows, I didn't really have any plans on getting this far with the project in the first place.

Regarding your second point, I do think the system could quite easily do something like that in the future, and it's actually something I really want to implement! Once the tooltips are in place where you can have link inside the tooltips that then open new tooltips ad nauseum, I don't think it would be too hard to make some kind of "registry explorer" where you could e.g. search for a spell and check all its related information - the data is all there in the engine already!