I use ghost and teleport with this build btw.
I understand some of your reservations about the weakness of Ashe in this build, and I can certainly tell you that sometimes this is a difficult route to go.
This is the build that plays Ashe for what she really is, an Assasin.
Many champions literally take 3-5 auto attacks before they die. You need to realize that this means they are on the floor in less than 3 seconds. Even the tanks, loaded with armor and HP, run away when I get this Ashe on them.
This Ashe plays on her strengths, not trying to feably bring up her weaknesses.
Ashe has a 30% slow, that is why you don't need boots with this Ashe. Champions have harder times getting away, and harder times catching up. Play hit and run if you event hink that they might be able to trap you before you can drop them.
Ashe has a very good stun. Keep them from getting off a stun on you so that you have the 3 seconds you need to put them down.
You can come up with a dozen scenarios that takes Ashe out, but the same could be said for every other champion.
For me, this Ashe singlehandedly turns entire battles in my favor, even ones that people thought were lost in the early to mid game.
Well anyway, all other things aside, it is fun. You naysayers should give it a try before you discount this strategy.