you get items that boost ur int lol

yes , the cops will come to ur house >=)

No, however there is a minigame that gives you run essence as a reward as well as points of which you can spend on more rune essence, or runecrafting robes, you will also get RC exp. if you create runes using ur rune ess reward during the mini game.

F2P: Air rune Earth rune Fire rune Water rune Body rune Chaos rune Cosmic rune Death rune Law rune Mind rune Nature rune

P2P: Dust rune Lava rune Mist rune Mud rune Smoke rune Steam rune Astral rune Blood rune Soul rune

Extra: Rune Essence(F2P) Pure Essence(P2P)

As you can see there is quite a few -Dd_rulez

Fire rune - 0554

Water rune - 0555

Air rune - 0556

Earth rune - 0557

Mind rune - 0558

Body rune - 0559

Death rune - 0560

Nature rune - 0561

Chaos rune - 0562

Law rune - 0563

Cosmic rune - 0564

Blood rune - 0565

Soul rune - 0566

Steam rune - 4694

Mist rune - 4695

Dust rune - 4696

Smoke rune - 4697

Mud rune - 4698

Lava rune - 4699