- For the price of Normal Pet (without skill) maybe 1000 gold is enough. What do you think?
I think I'll go with Phanjam idea. 500 gold is enough for just a skin.
- It seems to require a sense of giving status to each pet, because so far we can classify Pet into 2 parts, Slow Pet & Fast Pet. Maybe you can increase attack for slow pets. But you have to be careful, because if it's too strong it will look over power, because most of those who have low attack speed are mostly Giant Pets.
You and Phanjam seem to prefer an increased damage, so this is what I'll do.
And yes, maybe I won't double the damage if the attacks have a 2 seconds animation, probably a little less (someting like +75%)
- If you see most slow Pet is a giant size, maybe you can add Def & HP to compensation for being slow. 
Not for the phase 1, only the damage will be changed.
- I understand what you are worried about, if you give the attack speed too high or the attack is too strong it will affect the damage skill too, then it will be too Over Power for phase 3.
Well no, the skills should not be affected by damage or attack speed changes, because spells like fireball and frost do fixed damage.
Even if skills use weapon dps damage, both Damage and Attack speed will affect them, so it will be balanced for the pets.
The problem I had in mind is for the stats display.
The attack speed of all pets is 100, but for Troll King for example he still will be very slow.
Players won't understand why he is so slow with a normal attack speed.
- In phase 3, how many skills will you give to the Pet?
- Does each Pet have a unique ability?
- Will you make the skill for Pet (Phase 3) 0 Mp cost?
It's a little early to talk about phase 3 but I can say what I have in mind.
First, adding one or two unique abilities for each pet would be totally insane, there are too many pets.
I thought about that (and it doesn't involve merchants) :
- As I said before, each pet will start with different stats
- Each pet will start with a 'talent', that would be more an affix than a skill.
Examples : Bleeding bite, Regeneration , knockback attack, knockback resistance, increased critical chance, ...
- Each pet will 'unlock' a skill at levels 30 and 60. These skills would come from a common library.
Examples : Pet growth (+50% size and + 50% damage for x seconds), Frenezy (+50% attack speed for x seconds), elemental attacks, support spells (shield on owner that absorbs damage / owner growth / owner attack speed), healing skill, aggro skill, ...
I have to put in my library at least 30 different skills for diversity.
The way to implement skills that unlock at specific levels could be a stat watcher on skills based on the level.
- Do not forget to change the name Direwolf on Variant Pet to "Hellhound", because Direwolf existing in Synergies is different from that in Variant Pet. Direwolf existing in the Synergies are generally only Pet wolf that is larger than normal Pet Wolf size.
As the two dire wolves won't cohabit it's not mandatory to change the name.
- What do you mean by you won't be able to choose it with a new character? Is there no more double pet? like what you do for Essential Pet, no pet is double with Variant Pet. If so, it seems pretty good.
Yeah I mean synergies pets will be disabled at creation screen, but still works if you have already have one.
- Perhaps the Imaginary Pet Icon can be changed into a monster heros icon rather than left empty like that. I know it's just imagination Pet, but when if it's made empty it seems like there's something missing. 
No, I prefer the empty picture.