The Ranger, like all professions, has some issues of its own. With this post, I'll suggest improvements to traits, weapons, utilities, etc.

Pets

Make them deal a smaller percentage of the Ranger's damage by upping the Ranger's damage. Currently, pets are about 45%+. Make them more along the lines of 30%.

Separate pets between PvE / WvW and PvP. Buff their defenses in PvE and WvW.

Continue improving AI. 

Reduce or remove delay on f2 skills.

Weapons

Up damage from the following weapons: all of them. Especially the Greatsword, Longbow, and Axe.

Fix the Sword bugs (auto-attack rooting). Improve accuracy of 3rd skill. Speed up 2nd skill.

Condense the Long Bow's second skill into a shorter channel time. It's an inferior Unload that takes about 3 times as long to perform. 

Give the class some dedicated weapons. With the current design, every weapon, with the sole exceptions of longbow and shortbow, is trying to be both direct and condition damage. MH axe could benefit from being a direct damage-oriented weapon, as could the Greatsword.

Trait Fixes / Improvements

Beast Mastery Majors need to be rethought completely. Most of them are situational or outright awful.

Marksmanship Minors are worthless against competent players and completely useless in drawn-out fights (such as bosses). The entire design is bad because they are burst-oriented traits on a class that typically lacks burst. In other words, they are Thief traits, not Ranger traits.

Moment of Clarity is still pretty underwhelming for a grandmaster trait.

Move trap traits to Wilderness Survival where they belong.

Add something to Wilderness Knowledge. For example "All survival skills have a bonus effect," such as causing Sharpening Stone to add flat damage to your attacks, Lightnitng Reflexes to leave a Lightning combo field that stuns foes briefly, Muddy Terrain dealing damage pulses, and Quickening Zephyr losing the heal penalty.

Improve the Nature Magic majors. Certain ones (like Evasive Purity) are pretty lackluster for where they are.

Rethink the bow-based traits. I would combine Piercing Arrows with Quick Draw and add a dedicated Shortbow trait - such as increased condition dmage + duration or chance to inflict burning.

Improve might duration of Companion's Might.

Improve bleed duration from Sharpened Edges.

Add some cooldown reduction or a precision bonus to Honed Axes.

Trait Compression

Combine Martial Mastery with Two-Handed Training.

Combine spirit-based traits to make them take up 2 trait slots, not 4.

Buff Beastmaster's Might and combine it with Signet Mastery.

Utilities

Spirits:

Improve health considerably.

Improve trait support.

Make "following" baseline, rather than a grandmaster. 

Make spirit skills ground-target, rather than a delayed point-blank effect.

Shouts:

Improve trait support.

Improve effects. Rework some if necessary.

Signets:

Reduce cooldowns.

Improve trait support.

Make Signet of the Hunt's active not suck.

Weapon Ideas:

Rifle 

Racks up vulnerability with a fast, 900 range auto-attack before finishing them with a 1500 range burst.

Off-hand sword

Direct-damage off-hand that parries attacks and punishes foes with a bursty counter-attack and a skill that throws your sword at the target location to be fetched and wielded by your pet.

MH Pistol

Inflicts rapid, low-duration bleeds from 600 range.

Every Guild Wars 2 Profession has significant issues. Bugs. Bad traits. Bad weapons. Bad Utilities. Bad elites. You name it. In this first post I will focus on the most basic profession, the Warrior. I'll touch on the other professions in future posts.

Why the Warrior? Because it's essentially the "first profession" of Guild Wars 2. Simple. Easy. Popular. Relatively few issues.

Bugs are a basic issue with only one solution - fix them. As such, I won't cover them.

Trait Fixes / Improvements

Add reduced cooldown traits to each weapon, even if it's only 10%. Traits like Dual Wielding (weapon offhand cooldowns), Axe Mastery, Blademaster, etc. should give CDR.

Improve Longbow trait support. The range increase should be baseline, with Burning Strings as the trait with added Cooldown Reduction.

Warrior's Sprint from 10% - 15%.

Add reduced Stance cooldowns to one of the stance traits. 

Trait Compression

Combine Lung Capacity and Vigorous Shouts as a Grandmaster.

Combine Deep Strike and Signet Mastery. Nerf one or the other if needs be.

Weapons

Main Hand Axe - Improve Triple Chop. People weren't "accidentally" cancelling it. It does less damage than the rest of the chain.

Off Hand Axe - Improving Whirling Axe is key. There is little reason to use it outside of bleed-stacking with a MH Sword. While increasing the damage is a basic solution, a more interesting one might be to add cc immunity, projectile reflection, might stacks over the duration, OR increased movement speed.

Off Hand Sword - This off-hand is currently lacking as a whole. I would add a leap to Riposte to counter ranged attacks and cause Rip to deal slightly increased damage based on the number of bleed stacks on the foe.

Utilities

Allow physical utilities to work underwater. Some might need reworking for this.  The skills themselves may also need buffs - with the exception of Bull's Charge. 

Fix the Endure Pain bug - make it last the full 5 seconds.

Shouts and signets are largely fine - Dolyak might need improvement.

Improve Banners to be comparable to Shouts. 

Elites

Give Rampage a form of consistent anti-kiting. It is lacking in terms of constant pressure.

Future Weapon Suggestions

Off-hand Torch 

Like the Warhorn, used to inspire allies, granting them might pulses while burning foes. Can be thrown to create a straight-line fire field. 

2H Axe / Halberd 

Slow, heavy hitting attacks. Focused on pulling foes to you from a short distance, immobilizing them, and unleashing its powerful Burst Skill - Execute, which deals more damage to foes with lower health.