Pet advise pls

I have been leveling a pet without giving much attention to pet evolution, and with my pet at level 13 just discovered a pet guide. I have been putting almost all attribute points into marksmanship and only what was left over into my pet. He is now 'playful'. I understand it's near impossible to go from playful to elder.... should I start my pet over and spend more attribute points to achieve elder evolution or just stick with what I have and evolve to hearty ? Elder looks like the preferred path if I'm reading the info correctly ?

Pet guide is out of date.

These days there is the menagerie (A location that you can get to from the Great Temple of Balthazar area).

Once you get a pet to maximum level then bring it to the menagerie, once you release it to the keeper, you can then have them spawn any evolution of that pet you like.

More information: http://guildwars.wikia.com/wiki/Menagerie

have you looked into the zaishen menagerie yet?
reguardless of the evolution your pet is now, get it to lvl 20 and turn him in, then you'll be able to pick the evolution you want for the pet without the pain in the butt "training" for your pet.
http://wiki.guildwars.com/wiki/Zaishen_Menagerie

Thanks for the info, you saved me a lot of pet training

In addition, you can use Balthazar Faction to unlock pets and pet evolution if you want to do so. Once unlocked you can use Wynn to spawn one to charm.

I hate spending Balthazar faction needlessly, so I'm leveling pets through regular play on my A/R crit barrager, who only has 4 Beast Mastery and Never Rampage Alone & Comfort Animal. The pet really just serves as an extra meat shield. Point being, without any "training," the white tiger I'm about to turn in to the menagerie just hit Level 20, Elder.

So clearly it's not that close to impossible to evolve from "playful" to "elder."