I would suggest to revamp pets and give rangers possibilty to choose Beastmastery specialization (you may call it Petmastery), alongside with existing ones. In WoW with Beastmastery hunters do more than 50% of their damage by pets.
Meanwile in gw2 I laugh at pets being on the loose, uncontrollably attacking targets that are not intended to be attacked, one-shotted by bosses, standing still in the aoe circles. And pets damage is also insignificant. And it is quite irrelevant what pet you use.
Secondly, rangers should have ability with a burst damage.
Ofc these ^^ must be in balance with overall performance comparing to other classes.