I think pets should get abilities faster and get better abilities like unicorn instant of of +30 wise. It took 2 hours for me to get my pet to teen! So I suggest that Kingsisle should bring xp down or make games give more xp.
I'm sorry you didn't get the talent you wanted. But this is part of the pet training process. Not every pet has good talents in the pool as a first gen, and even if a pet has one of the talents you want, it takes multiple hatches to get a pet with the talent pool you want for all five talents. If this was changed now, people who have spent the time, effort, and gold for hatching (such as myself) would be outraged. It isn't meant to be easy. Having a pet with a heal talent, as you stated in your example, is a huge advantage, so there is no reason it should be easy. It is possible if you can hatch with someone who has the talents you want, which is what you need to do.
As for how long it takes to level a pet up, it will take you longer the lower level you are, as you have less energy and get lower level pet snacks as drops. However the pet snack issue can easily be resolved. You can get buy snacks at the bazaar up to rank seven, though they do cost more. A good rank six on to get is the Glowing Star Fruit, as is quite cheap, and since it gives 6 xp you can get 10 xp per game by using it. There is no reason it should take 2 hours to get to teen if you do this. Another way to get snacks is to garden, as many plants give snacks, and some even give mega snacks. If you don't want to wait for energy, simply buy an energy potion from the crown shop. They aren't that expensive.
Of course, even doing these, pet training can be time consuming, since the amount of xp you need only goes up from teen. In regards to that, I will say this again. It is not meant to be easy. You want a perfect pet, you need to work for it. Pet stats are a huge advantage, especially at lower levels, so you need to be willing to put in the required effort.