Strange, at least to me, that you would question what you did. That's the way we always did it. Put the clutch together, checked the stall RPM, and adjust accordingly. As long as the clutch was holding the engine at peak torque RPM, that's all we ever cared about. One point of caution, I'm assuming your clutch is not completely worn out! lol. You wouldn't want to compress the springs drastically, it might affect your top end.
Spring pressures go DOWN with use/heat. That would mean that the engagement is lower with used springs that new springs of the same type/size/configuration.
Springs do not get stronger with use, they get softer.
If you had to turn the spring adjuster in (clockwise) to get to the desired rpm, it could be because of not enough break-in time to seat the discs, excess air gap, oil/contamination of the discs, assembled incorrectly, machined incorrectly, etc. probably several other things I am forgetting off of the top of my head.
As long as your spring heights are within specs, you should be fine. Keep in mind also that the spring pressures increase pretty much linearly as spring heights are lowered.