Is my DM making OP PCs too early in-game?

So, my DM is doing a homebrew campaign where there are special dragons whose spirits are bound to a person through a mutal contract-like system. As a PC is granted the power of the Dragon Spirit they undergo a trial and the rest of the party can aid in completing the trial. Right now, our DM gave the Dragon Spirit power to a lvl 4 Rogue and gaining that power leveled him up individually. That, is not my concern. My concern is that from what I heard from the Rogue's player, is that the details of the Dragon Spirit's power was a 3-page long PDF with a list of benefits/features. 

Now, as a fan of Critical Role and all they do, I remember in the final arc of the Vox Machina campaign that the party earned their Blessings of the Gods when they were Tier 4 and those Blessings were only a couple of sentences long. Another thing about my DM is that he only lets his players go as far as Tier 3 at maximum

So as the Thread's title title suggests, is my DM giving us too much power at lower levels? If so, what would you all suggest he'd do to balance everything?

Three pages sounds a bit too long.

But with the power scaling, also depends on what he ends up throwing at you. And without details of the powers hard to know how much is flavor text and how much is "Oh, this is gonna get crazy."

It’s impossible for us to say. 
A page count in abilities doesn’t mean anything. Could be lots of it is flavor, or a lore dump, or ribbon abilities, or over complicated, or maybe your DM is really verbose. Could be that every benefit comes with a drawback, and it takes a lot to explain it. Could be there are powers that scale with the character, and your DM wrote it all down at once.

As far as balancing, that’s the easy part. If the DM cranks the player’s powers up to 11, it’s pretty simple to do the same to the monsters. Though at that point, you kind of have to wonder why you’d bother as it’s a lot of work to just end up where you started. 

Is this a new DM for you? If you’ve played with them before, did everything work out? Sometimes DMs don’t know what they’re doing, but sometimes you just need to trust them. 

I am going to throw out another problem that might exist that is separate and apart from power:  People want to play the content they signed on to play.  If you are playing a rogue, you likely picked that class because you enjoy the particular playstyle of that class - high dex, a lot of skills, and trying to get one single powerful attack instead of a bunch of smaller attacks.  Same goes with every other class in the game.  Related, each player thus wants to have their specific role in a party - a person is playing a rogue because they want to be the party's stealthy skill monkey; they do not want, say, the Paladin to turn around and be able to do that role as well as it steps on their roguish role in the party.

There is nothing wrong with the DM giving additional benefits to players, provided (a) those benefits are provided fairly (not necessarily equally - if all players have the ability to make a dark bargain, but some choose not to take it, that would be fair even if it is not ultimately equal) and (b) those benefits are additive to the content players want to play, not subtractive.  A DM's abilities are considered subtractive when they either eclipse the abilities chosen by the player, often through bad power balance as compared to the player's choices, or when they blur the line between party roles, thus subtracting the unique identity from any given character.

Without more information, it is impossible to judge if that is what is happening here - but those are things you should be on the lookout for as you play this game, and might want to have a conversation with your DM if you feel the DM is trying to force you to play a certain way (or power creep you into that position) or is otherwise giving abilities that make the game less fun.

I've played with this DM for years. We're pretty linear in campaign progression because we only meet once per month. I don't know if these powers will scale yet. It'll be some time before my PC gets his own Special Powers and share that here. 

Honestly, I'd see where it goes.  Your DM might have decided to make you OP so he can throw Party Killers at you.

Yeah, don't I know it. He threw a gelatinous cube at us when we were in a tight, single-file garbage chute. He loves those things so much; he forgot about how much damage they deal as it passed through us...