Hey there XinXin, magma is a decent pet for rogues. I suggest you slot in magma's happy bonus "Nightshade" and keep magma's arcane ability as it is.

Save up the 650k to at least 2-5m+ to buy good gear/pet.

Heroic shadowlurk/gloom/fenris/breezaga are decent pets in your situation, then you can move on to Mardios, Shady and surge, nekro, mishi, toor.

Get venom set first. Then upgrade to the swamp arcane ring & amulet.

Get endless set once you've reached Lv66, then upgrade the set to tainted if you've got enough excess gold. Or stay endless set + any wep of your choice.

A good rogue build is, Pierce/shadow bolt/nox/aimshot/ and speed + ignore mana ultimate.

10/10 nox mastery

10/10 shadow bolt mastery

You're welcome, have fun!