Cutting straight to the chase...
Problem Areas
1) Shield vs Heal
Shield I is probably the only level of this skill where you can say "yep, that's pretty good" and that only lasts from levels 2-5. After that, points in shield are pretty inefficient.
When comparing shield vs heal efficiency, shield has 1 glaring weakness. It does not mitigate white damage damage based on armor or dodge. Auto-attcks and creeps do 100% of their damage to shield.
So 2 numbers to show that shield stats are actually kind of neurotic in scale (an intern balanced it I guess
)
Shield
"Mana Cost", "Protection" / "Mana pool % Used" and "Efficiency" (lower is better)
400, 700 / 42.7% and 57%
560, 950 / 43.2% and 58.9%
720, 1200 / 43.4% and 60.0%
840, 1450 / 41.6% and 57.9%
Heal
"Mana Cost", "Life Restored" / "Mana pool % Used" and "Efficiency" (lower is better)
375- 600 / 42.4% and 62.5%
500- 900 / 42.2 and 55%
625- 1200 / 42.1% and 52.1
750- 1500 / 42.04 and 50%
Hey what a surpise, shield I is good stats wise vs Heal 1, then shield gets inefficient in both categories until Shield IV, where it gets a slight edge over heal in 0.44% in mana pool usage and also comes back to Shield I efficiency. (meanwhile the superior heal is getting better and better)
If we were to make shield efficiency scale in a more linear fashion instead of going all over the place in efficiency, we could have
Shield Suggestion
Mana / Protection
400, 700 (normal level 1)
545, 1000
690, 1300
835, 1600
This looks good to you? Yes/No?
2) Spike Wave vs Boulder Roll
Something is wrong with this skill even though it is nearly always used (because it's all you get to work with)
1) Boulder Roll is a stun which is far superior to a snare (it also has meta impact so it kills small units regardless of life)
2) The only advantage Spike Wave has in stats is at level 1 when it does more damage (350 vs 250) BUT it is equal at level II (500 vs 500) and surpassed by Boulder roll damage at level III (650 vs 750)
3) Mana Cost is insanely high vs Boulder Roll 750, 1000, 1250 vs 560,800,1064 (Difference is rougly 25% 20% 15%)
Originally in beta, Spike Wave was much stronger, with double the snare%. (30%,40%,50%)
So Some options
1) Restore the old Snare strength? (reg gets 30% at level 10 damnit!)
2) Scale the damage like boulder does? (350, 700, 1050)
3) Reduce Comparative % Cost vs boulder roll at lower levels? So mana cost would be 645, 920, 1250
4) Do all 3 of the above? *My vote hehehe*
3) Uproot vs Structural Transfer
Something is badly wrong with this skill.
1) Structural Transfer heals Rook
2) Uproot costs way more mana to use
If we were to compare the % of natural mana pool used to cast Structural Transfer on Rook, Uproot should cost this on QOT
Uproot 1: 280 vs 425
Uproot 2: 390 vs 585
Uproot 3: 575 vs 745
Uproot 4: 735 vs 905
Should uproot also have some ancillary ability or affect? (I think it should) eg: Structural transfer damages towers, with a secondary effect of healing rook. If yes, we could (or should depending on the affect) do a "taking damage breaks effect" like wings of the seraphim because 1) Uproot is not interruptable once fired and 2) QoT has shield, to protect this effect from being pointless.
If we agree to some sort of ancillary ability on Uproot, it should probably be based on damage, because uproot damage is synergized by compost, giving another reason to take compost with uproot
When coming up with an effect, as suspension of disbelief, roots do extract mineral nutrients. 
So any suggestions for uproot ancillary affect?
4) Compost vs Soul Power
This skill is just all around bad
1st off it is badly bugged. (compost VI cannot be met, and getting 3 extra kills resets the effect level timer)
It is fixed in uberfix, and from a Damage perspective 1 point of compost grants up to effect IV so it has the potential to do OK damage with 4 shamblers. However any additional points are complete wastes.
Soul Power Damage
I: 20-100
II: 40-140
III: 60-180
Compost Shambler Damage (consider 4 shamblers and uberfix)
I: 16-40
II: 24-48
III: 32-56
Compost Uproot Damage
I: 200-800
II: 400-1000
III: 600-1200
The maximum damage potential is pretty terrible on Shamblers, and gets worse when you consider attack rate. But the
uproot damage it actually pretty good when you compare it to uproot itself and structural transfer.
Personally, I don't think QOT needs 3 equal minion buff skills to choose from (Entourage, Compost, Morale) so I am wondering if there is some additional buffs we can add to Compost II (grants effect V) and III (grants effect VI) instead of scaling the damage to make it more equal to other skills. (you would probably never be able to fit all 3 skills into a build, making the choice mostly moot)
This skill would be further useful if uproot had some other affect attached to it based on the damage it does.
Looking for suggestions...
5) Entourage
This skill competes directly with Morale with the exception it boosts only Shamblers, and ends in Tribute @ Level 15
At one point in a patch Shambler damage was increased and this skill was decreased. (originally it was 10 dmg per level, now it is 6)
Assuming Max Minions (4 shamblers, 6 level IV Idols)
1 point of morale adds 23.9 DPS
Adds 50 Life to each minion
Assuming 4 Shamblers
1 point of Entourage adds 12 DPS
Adds 165 life to each Shambler
Suggestion
11 damage and +5% attack speed per level makes 3 points of Entourage scale up to morale in DPS.
The benefit of taking Entourage over Morale
Shamblers hit multiple targets
The life boost is higher
Entoruage leads to Tribute
but...
You need to invest 6 points (Shambler III, Entourage III) before 1 point in entourage scales in DPS to morale
Morale increases attack rate by 2% per level, so will still pull ahead slightly in DPS if you invest more than 3 points in it (morale IV -> VI)
This is good? Yes/No? I think it is.