Questions about Marksmen Itemization's Impact on AP on-hit

The marksmen itemization changes are impacting a very important item for a couple of ap champions who build on-hit, that being the Runaan's Hurricane.

Is there any Rioter on the team who can answer a couple of questions regarding this?

These changes will mainly impact Teemo and Kayle, the two AP champions most likely to build the item which is now no longer an efficient purchase on them.

Questions:

Both Kayle and Teemo rely heavily on this item to have presence in terms of both waveclear and teamfighting. While the changes to Nashor's Tooth and to Guinsoo's Rageblade seem to be intended to offset the latter, it still leaves both champions vastly nerfed in terms of waveclearing capabilities, with Kayle now requiring multiple more auto attacks at a fairly close range and Teemo requiring the use of his ultimate charges in order to efficiently clear waves. Is there anything currently being looked into to offset this impact, or do you feel that the reduction in waveclear is appropriate? What or why?

For Kayle in particular, if the loss of such a core item appears to nerf Kayle too heavily, what do you think an appropriate solution would be? To refocus her as the burst mage she once was? To make her more viable on an AD centric build (I realize she can build AD currently, but there is no refuting its inferiority to her AP builds)?

For Teemo in particular, Runaan's was Teemo's only reliable way of getting down some aoe (in this case multi-target) damage on the enemy team. Do you feel that the changes to other AP items, particularly Nashor's as currently Rageblade is not a frequently built item on Teemo, is enough to supplement for all of this damage reduction? Most of teemo's damage stems from on-hit, and his on-hit damage output in teamfight has now been reduced by up-to 2/3 (in reality it's probably more like reduced by 1/2 in teamfight, still an impactful change). Do you feel that Teemo may need to be rebalanced around a decidedly non-teamfight style with this change? Keep in mind that his semi-recent additional of lobbing shrooms seemed to be intended to take him away from this style.

Lastly, do you feel that these champions should be compensated at all, or do you think depriving them of this damage is good? Why? Their kits are considered by some (read: many) to be oppressive, and Runaan's certainly helped them to keep their kits viable in the late game.