Well, I showed you my QoT build IN1 so I will post it here... it is offense 1st, then switches to defense as the game progresses. Although it can fight some DGs very well 1on1, it's ultimately meant for allowing you and your buddies to focus 1DG and end them quickly. If you have an LE on your team, this build is goddamn ridiculous. You have alot of snare and white damage potential.
1) Shamblers I
2) Shield I
3) Ground Spike I
4) Ground Spike II
5) Shamblers II or Spike Wave I (depends if you are in battle or not)
6) Shamblers II or Spike Wave I (depends if you are in battle or not)
7) Spike Wave III
8) Shamblers III
9) Mulch I
10) Ground Spike IV or Mulch II (depends if you are in battle or not, and how much life you have)
11) Ground Spike IV or Mulch II (depends if you are in battle or not, and how much life you have)
12) Spike Wave II
13) Shamblers IV
The games go past this point?
Max shield, get mulch III / Goddess.. doesn't matter much after this...
Ultimately, you get crazy insane DPS out of Ground Spike IV, 4 shamblers, 2 siege and 2 monk idols.
Pros: The damage output is sick, and the snare means the enemy usually isn't escaping on foot
Cons: There is no shield support, except for the one point so you can still be the typical early power house QoT.
I also agree with you on mulch. You don't need Mulch I early, but you do need Mulch II shortly after 10
Oh, and you take shamblers 1 at the start so you can cast them at the health crystal. Getting shield at level 2 is no biggie.
One more thing... on cata you do not push the portals with this build (though you can). You push the middle to be most effective. Those towers mean jack to this QoT and are gone in seconds when she attacks them. The converged creeps are gone in seconds too, so you get a good build up of friendly units. Then you ground spike and attack the cit as you can.
This is why I say the game doesn't usually go past 13. There is no need if you are winning, you push up the middle, and kill all creeps and the cit goes down fast under hit and run ground spikes.