Scurvy_Platypus
Explorer
Oh believe me, I'm making this as easy on myself as possible. My cleric, for example, pretty much cribs Lay on Hands and Mercies/Cruelties from the Paladin/Anti-paladin (I'd sub the Paladin with either SGG's Templar class, or a Paladin variant without Mercies, like the Divine Defender), borrows a few Oracle Mysteries, and repurposes several cleric powers from Monte Cook's Book of Experimental Might. Most of this project involves shunting around existing powers from various sources into a playable class.
Something like this Pact Magic book you recommend could also be useful. I also like the idea of using something like M&M (I'd use TrueSorcery) to convert spells into powers.
I would urge a slight amount of caution. Different companies and different products have different sensibilities in terms of "what's balanced". So if you start pulling from multiple sources and frankensteining it, you start to run the risk of having uneven powers; possibly within a class, probably in comparison to other classes.
That's one reason why I suggested going with M&M or something. You basically want a single framework that you can run _everything_ through; that'll at least give you more consistent results and allow you to tweak/tune things easier.
So for example, if True Sorcery really turns your crank, use that as the basis for building everything. I seem to recall it functions on a "drain" principle, so that might or might not work for you. The important thing really, is being able to duplicate effects. M&M's power system, True Sorcery custom spells... whatever.
There's nothing stopping you from grabbing powers from any class or supplement you want. You just wanna know how what you're grabbing is going to play with what you've already got.
Another advantage to working with something like an effects based set of rules, is when you're looking at the theoretical cost (either in terms of Energy, Save DC vs Fatigue, whatever) of a power; if it's substantially higher than other powers of the "equivalent level" then it seems like a candidat for being bumped up the food chain.
So you'd have something like really cheap or limited powers can be At Will. A middle of the road cost ("standard") winds up being an Encounter power and really expensive ones might wind up being Dailies. Or whatever.
Just something to think about. Lord knows you shouldn't simply take my suggestions for everything, but give a think. That way you're more likely to be designing in a consistent space and it'll be easier to start troubleshooting when things go pear-shaped.
And when you're dealing with the 3.x spell system, that's pretty likely.
