I am very new to League as i just started playing mid Dec 2017. Kayle is my fav champ and i have done a lot of research on her with mobafire, and 3 other websites. I have had a lot of 20+ kills with 2-4 death games running Kayle. I am only level 25 so i don't face expert players, i face level 20 - 48s depending on their skill level. I have played other champs and roles including jungle with extensive reading/researching and have yet to find another champ to favor as much as Kayle. Feel free to leave constructive opinions under the comments section, i am always looking for different ideas on what works for other Kayle players.

Only change i make from Top lane to Mid is switching the Teleport Spell to Barrier as Mid Towers are much closer therefore teleport isn't needed. Mid lane has the potential to be a very dangerous, if not the most dangerous lane in game. The enemy jungler cuts through mid lane often to do their camps on Top or Bot side, so mid lane ganks may happen frequently. As well, Bot and/or Top laners occasionally may start pushing Mid once they take their respective lane's first enemy Tower down.

I feel Lethal Tempo is much better than Press the Attack in low to mid game especially with the 8.1 patch attack speed nerf to Kayle. Coupe De Grace to me is better than the other 2 bottom choices from the Precision Rune Tree as its pretty much a guaranteed kill against enemies with 40% or less health.
I prefer Manaflow Band over The Ultimate Hat as i find even with Doran's Ring i tend to run out of mana low to mid game and Kayle's ult is already on a fairly short cd.