Quote from KajaGrae >>

Few thoughts for balance.

3rd level: Your wording giving it extra rage damage and an elemental damage boost all the time, at 3rd level, is far too great of a damage potential at that level, especially with bonus action returning. The 3rd level ability sets the tone for the class. Your theme here is throwing. So, within the power scale of a 3rd level ability, the start should be something along the lines of "All weapons thrown by you, immediately return to your had once the attack is resolved, regardless of outcome. You can reuse the same weapon if you have extra attacks. Weapons thrown by you benefit from your rage damage bonus while your rage is active." That way, you don't worry about a bonded weapon like a warlock would, and instead, you wear a totem of some sort for it, it sets you up for 5th level extra attack, and you add your rage bonus while raging. 

At this point, that ability right there is enough on the power scale, but let's move on. 

6th level: Here, this is good point to add in your elemental flair. Chose your element, and scale it. d4 now, d6 at 10th, d8 at 14th. Now, that might not seem like a lot, but lets juice it up with some Barbarian flair later.

10th level: Here is where you can now imbue other 1 handed weapons without the throwing property, to make them have it. Let's give them a range of 20/60. Let's also double up the range of simple weapons with the thrown property, giving you a rangier option for slightly less oomph. Here is also where we juice your elemental damage. Now, when you crit, Brutal Strikes also effects that damage as well (stay bursty my friends).  Let's shy away form the heavy and two handed weapons for balance reasons. 

14th level: Here is where you can get a little crazier. Sub-Class capstone! Keeping with theme, I would go with: "You throw you weapon, and roll to hit every creature you chose in a 10' line out to your weapons maximum range." recharge on short or long rest. Here is your ricochet! Notice how the wording removes that pesky disadvantage to the over normal range attack? booya!

Keeps your theme, tempers it down to fit more readily with the power scale, and gives you some fun options on play style. now your Barbarian can lay the smack down from all over!

I didn't add the "counts as magical for resistance purposes," as you should be able to get yourself a magical weapon fairly easily as a weapon-centric class, and it keeps us more in balance lines when considering the other parts as a whole. Especially since ammunition is not an issue here. 

That is so good. I think that should be good and I like the capstone ability. 

Huzah! Many minds make light work!