Minotaur Mastery feat?

[Mork]

So I've been playing in a campaign as a minotaur for a couple of months now, and just reached level 7 (barbarian1/battlemaster6), so I get to choose a feat and I was thinking of something to help make my minotaur abilities more usefull, what do you guys think balanced? overpowered?

Minotaur Mastery:
Pre-req: minotaur
You have taken the natural abilities of your race and trained them to a fine art
-When you take the goring rush action, your melee attack deals an additional 5 damage
-When using the hammering horns ability you can also choose to shove a target prone
-You get proficiency in athlethics if you are already proficient you get expertise in athletics.

It is heavily drawn from the charger feat, the shield master feat and the new skill feats in UA.
What do you guys think? I might be able to downgrade the athlethics part that the proficience/expertise is only applied when doing something in combat (grapple/shove etc.)

[Torrin]

Looks find to me, if you are drawing from other feats, make sure that your feat is near the same power level.

[ThurlRavenscrof]

First ability looks fine. I'd limit the second ability to only work on a creature size large or smaller but other than that it's fine. Third ability I world worry about as a DM because it's pretty easy to abuse with your one level in barbarian - basically every time you rage, all your grapple checks would have like a +10 and be at advantage... But if I trusted you as a player I'd be cool with it. Especially since there are way more OP things out there