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Answering this again for clarity... Assuming the melee weapons and bow are of similar quality, melee will be higher dps. However, with the use of the trueshot disc, which isn't available until level 55, bow damage will be higher than melee for two minutes. The remaining seventy minutes melee will be higher dps. Thus, without the use of trueshot, melee dps will be approx double that of archery dps. Even at level 60. Even with the best bow in the game.

You listed one DPS and 3 tank classes. Might put some fine print on that...

In group content levelling up file warrior under dps.

From the day he gets snare to the day his defence skill stops raising Ranger is the king tank!

A ranger, sham or bard can tank any content with the right gear and a quality slow (for the later levels). Being able to snare/root/flame lick puts the ranger above most the other tank classes for sake of aggro.

A problem for rangers besides stat itemization is as you mentioned skill caps. The bigger one (I feel) is fighting the dogma that they can't tank. If you are expending a ton of energy trying to prove yourself into a role that can be best spent elsewhere. Hell...I'd rather turn my LFG tag on and go kill hill giants in the Karanas than queue up the Powerpoint presentation and explaining what a Swarmcaller is.

More advise to the OP though:
*Get used to Harmony and using track.
* Learn to skim it on the move and chain pull.
* Snare everything that might run.
* Learn how to root park when you get that skill.
* Get up to about lvl 60 in Fletching and make some low dmg 150 range arrows for pulling.
* Keep your tank thorned if no mage or druid in the group (srsly)

The gear game is a tough one to win but being great at your class is free...it just takes time and some dying.

Ranger tank best tank unless raiding.