Questions for Zilean passive

I haven't been able to get on the PBE, so I won't be able to personally test new Zil... but he was the first champ I bought, so I'm invested in seeing him do well... so questions to watch out for and immediate suggestions:

1- how will this new passive store up? Is it all consumed when he levels someone up, thus xp wasted between the instading is ready and when it's applied? Or could you perhaps save up enough down bot to run up top, passing out love to the jungle and mid on your way? (I'm hoping for the latter).

2- any chance of it having some kind of secondary effect when all allies are 18? It had better be strong early game to end up useless in the end game.

3- Are we taking a look at W? The move speed softcaps make the difference between level 3, 4, and 5 negligible as a debut and still pretty minor as a buff. Even if the 99% debuff had no cap, it would still be definitively less powerful than a root because the enemy could still flash, dash, jump, charge, etc.

I'm really hoping this will be a step back toward LoL's anti-meta origins, when weird builds and lane comps were encouraged... everyone's losing their minds at the idea of Morde/Zil Bot.... and cringing at the concept of legitimate synergy instead of trying to identify other champ specific teams that may be more advantageous than picking a champ regardless of who your lane partner is. Personally, I'm looking forward to countering top Yorick with Solo top Zilean as a jungle support/gank securer.