I often forget Hydra is even an option at this point. It just isn't a cost effective item anymore. I mean, really. 3500 gold for what exactly?
As for garbage wave clear, I'll have to politely disagree. I generally E onto caster minions to wipe them out first then I proceed to last hit the rest of the wave after.
And you mentioned jungle. Again, I disgree with you there as well. Players generally invade 3 or 4 times out of 10 in my experience. And depending on where my bot camp is will determine which jungle item I buy first.
If I am going red first then I'll need to compensate for mana with
after which I take a dose or two of my
and go into the enemy jungle bot side where I either steal the enemy blue for them getting their leash top side or I find them at wolves or gromp where I either...
A. Manage to kill them early.
or
B. Force them into retreat.
Of course, I've the presence of mind NOT to stay for any camps after my brief encounter with the enemy jungle and, instead, melt back into my own.
With red, Wu can cheese any vulnerable target in the early game including tanks.
As for blue start, that's where I decide to go for an early farm strategy in order to maintain a strong bot side leash. This is when I start
since I've the mana regen I need for my first clear.
Crabs on both sides of the map are good for his early sustain, by the way. Enemies often forget those even exist with the exception of Kindred mains who are few and far in between and they hunt them simply for stacks and for no other reason.
To keep my jungle clear without having to back frequently I upgrade my potion to
because, as you mentioned, he has no built in sustain. And it's proven enough to maintain a competitive CS.
I will agree with you on one point, however. He is not an effective tank. A tank Wu deals no damage and simply dies slower than he normally would in team fights that go South and they often will if you are unfortunate enough to have a Wu on your team build tank.
Finally, the engage you mentioned is not at all how a good Wu would engage an enemy. E, Auto, Q, R is the legitimate combo and then you save W for an escape as needed rather than burn it on the engage. The only time Wu should ever decoy for an engage is if he catches an enemy alone and wishes to burst them down in an instant without giving them a chance to react.