So, I've recently started a DnD group and we're having loads of fun, so I thought I'd start homebrewing some stuff. Decided to start with a race, and goblins seemed like a good beginner race. Right now I only ask someone to go through to data given so far and tell me if there are any severe balance breakers and the like.
They are probably quite cliche, since they're some goodie tribes banded together, trying to form alliances with human/dwarf/elf nations. Hence the insight bonus.
Another thing I'd like to know are favored classes. I got druid and fighter as dexterity and constituion oriented ones, but can't really find any others.
GOBLINS
Racial traits:
Average height: 3´3˝-3´8˝
Average weight: 55-80 lb
Ability scores: +2 dexterity, +2 constitution
Size: Small
Speed: 5
Vision: Low-light
Languages: Common, Goblin
Skill bonuses: +2 insight, +2 intimidate
Race features:
Heritage of Chaos: -2 diplomacy, +1 to attack rolls, +1 to any defence
Goblin tactics: You may shift a number of squares equal to your dexterity modifier as an immediate reaction when you become bloodied.
Fearful reputation: You gain the use of the fearful reputation encounter power.
Fearful reputation: You feign weakness, but then surprise the foe with a vicious assault. Encounter, minor action, close burst 1, Target: one creature. Effect: Your next attack during this turn dazes the target. If the attack misses, you can shift 1 square.
Big thanks for the help!
Heritage of Chaos: -2 diplomacy, +1 to attack rolls, +1 to any defence
Big thanks for the help!
That's a breaker.
Do you have the Monster Manual for 4e? I'd recommend you look at pg. 278, because the Goblin has already been premade for character creation.
Are you trying to make a small vicious race or a race that runs away? You seem to have conflicting designs. They have a bonus to intimidate and have a racial power to daze an opponent but shift when bloodied and shifts if daze misses. I'm not sure what to make of fearful reputation. Granting daze or shift based on a latter attack seems odd.
As mentioned in Fireclave's Guide to 4e Race Mechanic Creation, penalties like your -2 to diplomacy are not done in 4E. A flat bonus to attack and defense is also not a good idea.
For a racial power I'd suggest some sort of fear power that gives you combat advantage against opponent(s). I'd drop goblin tatics as that seems to be another racial power. Maybe "goblin retribution" instead, +1 to attack (or damage) against an opponent who injured you since your last turn.
So what you have are the 4th Edition NPC goblins from the Monster Manual, but they weigh nearly twice as much, use Constitution instead of Charisma, move only 5 squares, and have Insight and Intimidate bonuses instead of Stealth and Thievery. As dulsi mentioned, 4th Edition doesn't do starting penalties, and a -2 to Diplomacy certainly doesn't balance the benefits you're given them.
As shamhat said, the +1 attack bonus is a deal breaker. If you want to create a feature or power that grants a bonus under certain circumstances, that's one thing. If you just give them a flat +1 to attack, you'd have to take away their other features to try and balance it. You're already giving them a great bonus by allowing +1 to any defense instead of a +1 racial bonus to Reflex like normal goblins.
You've reduced Goblin Tactics from an at-will power to a racial feature, which seems to power it down, except you're not only increasing the distance of the shift by an average of 3 squares at the start, that shift could be 10 squares by 28th level. In addition to that, you have it happening whenever they become bloodied, and a player could design the character around becoming bloodied on a regular basis. That should be reworded to add, "The first time you become bloodied during an encounter [...]"
The encounter power also doesn't balance well. In terms of balance, think of racial encounter powers as at-will powers you can only use once per encounter (much like multiclassing). I would consider changing it to a standard action attack power with the fear keyword that dazes the target until the end of your next turn instead of dealing damage and gives you a +2/+4/+6 (1st/11th/21st level) bonus to the attack roll. Racial powers shouldn't do anything on a miss; in general, only daily powers should include miss effects.
I'm also not sure why the attack is a close burst 1 that targets one creature. Powers in a close burst 1 should effect more than one target; powers with a wider burst may only effect one target, but the beauty of the burst effect is that line of sight is unnecessary. If a creature is adjacent to you, you already have line of sight and line of effect, and blindness will have the same effect whether the power is a close burst 1 or a melee 1. If you're trying to theme it as a fearsome roar that works in a burst effect or some such, consider changing it to "each creature in the burst" and reducing the effect: perhaps creatures hit by the attack take a -2 penalty to attack rolls or become immobilized until the end of your next turn or the like.
Heritage of Chaos: -2 diplomacy, +1 to attack rolls, +1 to any defence
Everything about this feature is bad. The -2 penalty to Diplomacy is bad because PC races aren't supposed to get penalties. Ever. No. The +1 to attack rolls is just too powerful for a racial feature. And finally, the bonus to defense is excessive because they already get a bonus to two defenses through their racial ability score adjustments.
Goblin tactics: You may shift a number of squares equal to your dexterity modifier as an immediate reaction when you become bloodied.
Pigeon-holing a race into needing a specific ability score to have one of their racial features function is not really very good design. You should learn from the Dragonborn, not repeat its mistake.
Fearful reputation: You gain the use of the fearful reputation encounter power.Fearful reputation: You feign weakness, but then surprise the foe with a vicious assault. Encounter, minor action, close burst 1, Target: one creature. Effect: Your next attack during this turn dazes the target. If the attack misses, you can shift 1 square.
BROKEN.
1) I don't know why everybody thinks dazing makes for a good racial power. It doesn't. It has so many effects that it's just plain overpowered unless you severely limit the conditions under which it can be used.
2) I know this isn't what you intended (but the power is still broken even without this), but with the current wording, the target of this power is dazes regardless of whether or not the attack hits or misses. In fact, with the current wording, the target of the power is dazed regardless of whether or not the subsequent attack actually targets it at all!
Note that theres dazing and then there's dazing.
A daze that ends at the start of the opponent's turn is significantly weaker than a daze that lasts until the end of your next turn.
Note that theres dazing and then there's dazing.
A daze that ends at the start of the opponent's turn is significantly weaker than a daze that lasts until the end of your next turn.
And the power in question specifies neither. 
Note that theres dazing and then there's dazing.
A daze that ends at the start of the opponent's turn is significantly weaker than a daze that lasts until the end of your next turn.
And the power in question specifies neither.
Right. No saves, no end. It is dazed FOREVER.
Right. No saves, no end. It is dazed FOREVER.
I thought that, unless otherwise stated, it lasts til the end of the target's next turn.
Or was that just in the minis? I can't remember.