a couple of questions

1). how do you get hearty..etc pets?

2). does the axe only have more dmg than the sword because it has a bigger dmg range or is thee another difference?

1) Look up the "ultimate pet guides" on the Guru board for everything you want to know about pets.

2) Axe does more max damage, sword has better average damage, 15-22 for sword, 6-28 for axe. What's the question?

axe vs. sword damage over time is roughly the same. The biggest difference is when you hit for a critical hit. Most people like the axe because it has a chance to hit for that higher damage. If it hits at the high end of that damage on a critical hit then you are looking at some real good damage.
The same can be said for a hammer but it's attack rate is much slower than the other two.

Axes have a slightly higher DPS than swords, but it's pretty insignificant. For most purposes, axes to the same damage over time as axes. However, axes inflict higher criticals; both have the same chance to crit, but a crit always does 4 (?) times the maximum damage; far more on an axe because of it's higher range.

Check the guru calculators; I'd double check my view, but Guru is being annoying.

Correction: Swords have a slightly higher average damage; axes however beat this when factoring in the higher criticals. Usually, the skills available to each decide which weapon you want to go.
http://www.guildwarsguru.com/calculators/guru_speed.php