No Mass Effect Relays in Andromeda....

Is this really obvious? Am I missing something?

Aside from me using incorrect descriptors, jumping system to system not cluster to cluster, still required Mass Effect relays in the OT. To warp from the Sol System they had to use the Charon relay.... The distances in Andromeda seem comparable if not even larger.

As mentioned above, the entire game takes place in only one cluster, the Heleus Cluster, so Mass Relays are not needed. To use an example, with the galaxy map in the Shepard Trilogy this entire game takes place in only a single point on the galaxy map. When we traveled in clusters in the Shepard Trilogy, we only explored a few systems where this time we explore every one. 

When it comes to travelling further and eventually will travel cluster to cluster, the ODSY Drive is a new mass effect drive that the ships use that eliminates the static discharge problem so we are able to travel that far, after all we used them to travel from the Milky Way galaxy to the Andromeda galaxy. That said it still takes time so I suspect we will discover something that acts like Mass Relays or we manage to create new ones.

Exactly
One cluster already is big enough
Imagina exploring every cluster from human, asari,turian,volus,salarian...
Mass relays were needed there
In andromeda only ftl is enough

Yes it is really obvious. may be you can start by counting how many clusters are in the game and how close that are to one another.

No it does not.

Yep. Like I said, you can see when you're using a relay and when you're not. ME2 makes it quite clear that you only need them when going between clusters, not when going between stars.

Oh, wait.... I was talking about the OP's confusion, not yours.

While I don't think that it's actually called the "Heleus Cluster" - I doubt it has a name in real world astronomy - I believe the Heleus Cluster is a reference to this:

en.wikipedia.org/wiki/Andromeda_Galaxy#Nucleus



That would explain the size of the black hole - at least in part - relative to the rest of the cluster. Even a supermassive black hole is no more than light hours accross. The cluster itself must is light years across. Meaning, the game designers took some artistic freedom to make the black hole appear more threatening...

Center of the Andromeda Galaxy (not the galaxy itself) in visible light:
(Linked from Wikipedia, taken by the Hubble space telescope)

That can easily be changed since ME is science fiction, they could just say the blackhole is several light years across and it's special. 

Of course you could be right and they just decided to make the blackhole really big for artistic reasons

Also the Tempest can travel 13 lightyears in a day so without knowing how long the Tempest takes to travel between systems, it's hard to guess how big the Heleus cluster really is. The time it takes in game isn't accurate because obviously it's shortened for gameplay reasons so we don't all bore to death waiting for the Tempest to travel. 

We'd probably need a few Reapers in order to build Mass Relays.

Which suggests you're indoctrinated.

Well the codex entry for kett starships mentions they use eezo cores to create an Alcubierre effect, a "warp" drive.
It's described to be as effective as relay travel, if less efficient.

I imagine it'd be a simple matter to reverse engineer a kett drive in time for the next installment. They do have a multi cluster empire, they know how to get around.

There is always the option to introduce natural wurmholes à la Wing Commander. Or the Jardaan had mass relay, star gates or something alike.

Finally, if we look at the revised ending of Mass Effect 3...