And to add to the pet merit category:

That's a very cool idea and I like it a lot, hope they'll think about implementing it! But it still wouldn't solve the Pet Scaling issue, and I doubt it would have a big impact on the Pet Survivability either.

As I mentioned before, I don't think a direct "Pet: damage taken -X%" (wether you get it through gear or merits) is the right solution to go, if anything it's potentially "dangerous" because it might make certain pet jobs too strong (especially BST) and require SE to nerf the class afterwise, and I don't really want a nerf >.>
Damage taken is currently fine imho, altough a few more gear options wouldn't hurt.
The thing they need to address is not the direct damage the pet gets, but the "indirect" damage, i.e. that from AoE that target your tank but end up hitting your pet too and yourself.
You can be healed by the party healer, but your pet has cooldowns to be healed/debuffed, so it's only right they take a certain % of reduced damage from these attacks, if they're not directly targeting the master or the pet.

A wide range of monster abilities are AoE around a certain target, easy to make a job trait for Pets that takes this into account.
Other abilities are instead AoE centered around the monster itself. For these abilities they could make so the Pet receives lower damage if he is below a certain threshold in the enmity list.