Maybe I'm not entirely grasping your overall methodology here. What happens if I buy your game? How would I have 'Thunder of Judgment' (since you obviously can't print it in your game as its a 4e power, and the point was to avoid duplication). Obviously I could treat your material as strictly a SUPPLEMENT to 4e, but doesn't that kind of miss the point? Granted, I could probably just play your stuff, and live with "some specific permutations are best", but I think that was what convinced WotC not to go down that path, its just simpler to name the best permutations you can find and call those the powers in your game! In a point based system the players are just tasked with doing that for themselves (which they might enjoy, I don't know that it is inherently bad).
Also, its possible that some point value calculations will be SO off that they exceed even sky blue.
The point of the system would be to make a relatively quick playing version of 4e that could use options such as feats/powers/magic items from 4e. But because some of the assumptions would be more balanced - such as any bonus to damage from a feat is a feat damage bonus, means there wouldn't be much chance of stacking.
It wouldn't be a full point buy in any case. It would be more:
Pick a power that allows option X to be chosen. Where option X is an encounter use class specific option. So as an example, Dazing Attack would be a melee 1w/i+stat power. Option X for Arcane Controllers would be to change it to a close blast 3 1i+stat power. Option X for Invokers is to make it have a 2nd target. Etc...
Think of it as being a cleaned up, "Basic 4e" that could use the options of 4e, but wouldn't have to do that. I'd do things such as making it easy to convert on the fly 4e monsters into Basic 4e monsters without actually using the defenses of 4e monsters. Things like that.