General

Going off of what @Versailles said about reducing delay by comboing LE+ Leap Tornado: You can cancel almost all of the ending bits of Mercedes animations by using stunning strikes, wrath of enreal, unicorn spikes, or spikes royale. You can also chain a leaf tornado right after a spikes royale-> wrath of enreal which puts you in the air for just enough time to do stunning strikes and an almost instant lightning edge.

[quote=marilanna]I can't get the hang of using Lightning Edge or Gust Dive regularly, since I've been away for two years. They are forever useless skills to me, the delay after LE annoys me too much[/quote]

You can use LE+Leap Tornado "combo", it'll reduce LE delay by a LOT.
(macro don't work, you need to press both LE>LP)

ninja edit: when using LE+LP your travel distance will be decreased compared to only using LE.

I can't get the hang of using Lightning Edge or Gust Dive regularly, since I've been away for two years. They are forever useless skills to me, the delay after LE annoys me too much

Use lightning edge and link it with a jump leaf tornado gust dive. From there you can repeat the combo by using lightning edge again. Personally I like to link LE with rising rush into Ariel barrage into rolling moonsault into wrath for vertical maps. For horizontal maps mainly use LE though

Honestly try timing your exp with various combos at various maps.... it's varies depending on the situation (map layout, damage range, monster HP). Generally Lightning Edge + (something it can chain to) seems to be fairly common for its mobility. If you can dig from old threads (ex. http://www.basilmarket.com/forum/2865363) there's better answers. Also use Wrath of Enreal when you can since it now counts as a chain.