I also feel like LeBlanc's W is really obnoxious, although I do feel like it is somewhat appropriate to have it deal a fair amount of damage so she has to actually get into melee range to deal damage to you instead of just nuking you with three abilities from range.
Something I feel would keep LeBlanc feeling like LeBlanc is if her W recast had her dash back to her original location (as opposed to blinking, like it is on live) and have her E's tether radius reduced.
The former would allow her opponents a lot more room to play against her because they would be able to read when she is traveling back to her original location and to trade with her when she dashes back, as opposed to when she blinks back and you have no time to react to her blinking back, so you have to chance a 50-50 in order to trade with her that isn't really a 50-50 because the LeBlanc player can still read your cast times and react to your play to make a decision to blink back to specifically dodge your skillshots.
I had a game playing against a LeBlanc as Lux, and I found that predicting when LeBlanc was going to return to her original location was a really good way to play against her, as I was able to cast my Q or E at her original location, and land them as soon as LeBlanc blinked back to her original location. This was basically the only way I was able to kill her all laning phase. I managed to have fairly decent predictions regarding her returns, but I feel like you shouldn't have to predict, and instead react to her dashing back, turning LeBlanc's W patterns from relatively free harass into a 50-50 into a more strategic game where you have to take risks to get the damage she has off of her W.
The latter also gives her opponents more opportunities to play around LeBlanc by forcing her to be closer when she tries to burst her down. She shouldn't be able to jump in, burst you down with both procs of her Q, her W, and both procs of her E while still being able to get out safely. She should have to work to trigger her E while still allowing her opponents counterplay against it.