Well, I'd like the ranger pets to work in some sort of amalgamation of previous ideas.
But first, ranger pets should NOT be permadeath. A ranger will have emotional ties with the pet as they've devoted time into it and seeing it die will probably create unnecessary stress and
to the ranger. But, without permadeath, pets may run unchecked. So, put their level cap at 20 (or at the ranger's current level, but this will create a difference from a 30 ranger to a 20 ranger). Now, since pets are not permadeath they will need a penalty for dieing. So slap on the regular 15% death penalty each time the pet dies, or (even better) slap a penalty on the ranger each time the pet dies. Finally, for the means of resurrecting the pet, I would recommend tieing a skill to beastmastery like "Animal Reborn" or something that simply allows the ranger to resurrect (or resummon, incase the map ends and the ranger can't find the pet) the pet. Give this skill a long cooldown so a Ranger can't spam it, and it should balance itself out (The ranger can bring and carry over their pet through PvP matches, but at the cost of a skill slot).
I do NOT want to see pets that die and must be refound and retrained. Leveling a pet over and over again is a grind.