By request, here are my thoughts on Lore of Life.
Lifebloom (Lore Attribute):
This is a pretty cool attribute. Free healing is very nice and you can use this to keep a choppy saurus character or a stegadon going long after it should have succumbed. Very nice.
Earth Blood (Signature Spell):
Nice spell. Regeneration is always nice and with Throne of Vines it's working half the time. This is somewhat negated by the sheer amount of flaming attacks available to most armies now but it's still pretty good to have. You're going to want to use this in conjunction with Throne of Vines and the other spells in this lore to create a really nasty anvil unit your opponent will never get through.
Awakening of the Wood (1):
Decent spell for its cost. Unfortunately, I don't really foresee many people getting any use out of this. With the random terrain generation chart, I at least don't foresee myself putting anything in a Mysterious Forest that has such a potential to start munching on my guys. Luckily its a good spell even when not in the woods.
Flesh to Stone (2):
+2 Toughness is fantastic. +4 Toughness is even more fantastic. This will make your opponent need 5s to wound you at best, 6s to wound you with Throne of Vines. This is a must have spell for this lore.
Throne of Vines (3):
This is the spell that makes this lore. It allows you to throw tons of dice at each spell with no fear of miscast and makes all of your spell but Dwellers Below even more fantastic. You will start every magic phase with casting this spell if you don't already have it up.
Shield of Thorns (4):
Great spell for your impossible to kill anvil unit. Get this up and it forces your opponent to seriously think about whether they'd rather dispel Throne of Vines or this in their turn. Every turn they don't dispel this (if cast with Throne of Vines), they'll have to take 4D6 S4 hits. That is just awesome.
Regrowth (5):
Bring your units back to life? Very cool. D3+1 is so-so for the point cost but D6+1 with Throne of Vines is truly very nice.
The Dwellers Below (6):
A fantastic spell against some armies. The last spell you will cast against others. Strength test or die is very nice against things like elves but against things likely to pass their tests, you are probably better off keeping all of your buffs going.
Overall Lizardmen Thoughts:
This seems to be the lore that everyone on the internet absolutely loves for their slann. It's easy to see why. Take a big old unit of temple guard, stick your slann in it, march it up the field, and give it 4+ regen, +4 toughness, bring back D6+1 casualties, and give it an extra 4D6 S4 hits in close combat every turn? That's just AWESOME!
I haven't tried it myself but when I really think about it, I don't see it as actually being that great on the table. If your opponent brings a badly unbalanced list, sure, you're going to dominate the magic phase and their is nothing he can do about it. But what it really comes down to is Throne of Vines. This is the spell your opponent has to stop. Without this, your battle plan falls apart.
You have two choices every magic phase, cast this spell with a lot of dice to keep it from being dispelled or go for the minimum. If you go for the minimum, your opponent can throw all of his dice at it because this is what he needs to stop. All of your other spells lose a lot of their effectiveness without it and will expire by the next turn anyways so you'll just have to recast them all over again and who knows how good your next magic phase will be.
What if you throw enough dice at it to make it difficult to dispel? Well, if you irresistable force it, that's fantastic and you get it. If you don't, this is where he whips out his dispel scroll or feedback scroll and we get to watch your slann implode. What if you do get it off and he knows he can't stop it with his dice? Well, then all he has to do is stop your follow up spells. If you've thrown a ton of dice at this spell, you're not going to have much left for your other spells. And he can just dispel throne of vines in his magic phase. On average, it only takes 2 dice on a level 1 wizard to dispel it. 2 dice on a level 4 wizard is virtually a guarantee.
I think a savvy opponent that brings any decent amount of dispel is going to tear apart a Lore of Life list. Sure, if your opponent isn't so savvy or just plain has shitty lucky, you're going to tear him apart with this list, but with magic so random in this edition, I think this list relies too heavily on being able to be consistent in your magic phase.
There are of course some ways to mitigate this and try to make sure you have enough dice to do what you need to do. My personal recommendations are to always take The Focused Rumination on your slann and seriously consider taking the Forbidden Rod on a skink priest and a Power Stone on the slann himself. These will help you generate your necessary power dice on a bad winds of magic roll and enable you to recover and get things back on track. A Power Scroll to irresistible force Throne of Vines or another spell on command is also useful and should be considered.
As far as partnering this with Lore of Heavens on your skinks, look for synergy with Iceshard Blizzard to help get your anvil unit into combat and Curse of the Midnight Wind to make it even harder to kill them.