Ahhh, orianna vs zed definitely has a star rune. I'll mention it again when we show the rune. I'm getting the sense you will generally enjoy the inspiration path when we can preview more of it.
Paths: We chose 5 paths because... we grew to it. We started at 4, then kept going up to 5 (and once 6) and down to 4 over the course of development. 5 was how many we think we could deliver in a complete manner (measuring how long it got us to "good" for a lot of runes) by release, while appropriately challenging current design space.
Long term, we want more paths (that could change as we learn more though). The "testing decision making" runes like Store Credit and Magical Footwear we currently believe is the best place to grow for those new paths as well, but they are very unproven design spaces for League right now. But they also just take a LOT of new tech - the entire purchasing behavior for items had to be rebuilt to make adding these kinds of things easier - so we can't do all the things at once.
Internally, we've had different mixes of interactivity on runes. When it pushes too far, there was far too much to track. This got worse the higher MMR people were internally as well, since there was a greater desire to wanting to track all of that stuff as well. We also lost a lot of feel good functional "make sets of champions work" decisions. Like... "I need MS against some matchups as Aurelion Sol". We found the current mix a decent balance. Though, I'm expecting this may change a bit as the system is learned.
As more runes corner things or dev blogs come out, I'll also try to get these mentioned again.
