the whole point is that you USE your stealth to flank and enemy and pincer them with an ally. I've found that eve is still an amazing Ganker during the laning phase once she manages to hit 6.
now as fas as SOLO killing during the midgame and looking for picks on lone carries. this was completely INTENDED to give counterplay
Lust dust having the 1..5 second charge time for the disable was a premeditated design choice that has been present on nearly all assassins since the "assassin class update"
did you notice that 
has a 1.5 second Priming time on his W?
Or how 
had her burst moved to her SECOND auto attack?
has to wait for her daggers to hit the ground before her true burst is available.
has the 1.5 second "mark" prime
In other words Riot is all about COUNTERPLAY! Riot does NOT want Old eve back where she would just instakill you out of stealth in 0.5 seconds . Riot has purposefully increased the kill window to offer a more fair chance when an assassin is ahead. 1.5-2 seconds is what Riot considers a fair window for an assassin to kill you in.
I think another thing you are forgetting is that IF Eve manages to get a large enough lead then she probably wont need to wait for the allure part!. Eve will simply open up with a E out of stealth( which deals bonus damage) into a hatespike rotation and ultimate. You do not actually have to wait for targets to be at 30% hp to kill them with ultimate. That is mainly just a tool for dealing with tanks ( if Ashe only has 500 HP left you dont need your ultimate to deal 1.3k damage ). Eve's ultimate actually has extremely good base values and you can honestly just use it when a target is on half HP . same as 
waiting for the execute threshold is very often overkill so you want to avoid that if you can and instead just try to calculate how much you can do in a full rotation guesstimate from your targets resist.
In other words I think you are just knee-jerk reacting to new Eve after like >5 games. As you begin to play her more you will understand that her kit is an excellent blend of fair to play against and much more skill based when it comes to maneuvering Evelynn effectively.New Evelynn feels great to play and finally has a much more thematic and unique kill pattern and style compared to other assassins! If a Champion is too dangerous to attempt alluring (such as another Assassin Talon/Zed/Kha'zix) then just SKIP that part and open with E then use W as way of punishing their hard committal !. In a pinch Lust Dust is also a defensive tool so long as you make sure not to activate it. If you open on the target with E then tag them with Lust dust you can get the charm off if they attempt to fight you back. This sets up for free damage or a escape or maybe even a turn kill.
all I can recommend is that you continue to play Evelyn until all the little tips and tricks with her kit snap and resonate with you. she JUST came out 2 days ago so keep at her then form another opinion after about a week or so.
make it exceedingly difficult to engage/peg them, I mean you made a whole list of amazing Assassin items only, and then you made it so evelynn can't benefit form any of them, unless you make a bunch of mage/assassin items to counter that I don't see this working.
going to engage 
or 
, and Pegging 
is going to be a little fun too, she used to have a 70% run speed button whats the difference ?
