Habitat 7

I assumed it was because the Scourge made it too dangerous, but then why bother to terraform it as Ryder I?

Which is probably what happened to H-047c.

I really like this theory, as they did mention the atmospheric processor on Habitat 7 was caught in a "feedback loop" with the Scourge.

Could be that the Scourge damaging the Vaults on Habitat 7 and H-047c caused them to misfire, activate in the wrong sequence, not properly shut down afterwards or threw off the settings and instead try to create multiple conflicting biospheres on the same planet.

All Alec might have done on Habitat 7 was to shut down the system, while Ryder fixes plants by hitting the reset (or refresh) button.

Makes me wonder if if the conditions on certain planets we encounter in Heleus are actually reverting to their natural states, rather than slowly deteriorating because of some kind of problem with the Vaults themselves?

If the Vaults had been used to make those words habitable long ago, without the the Remnant to maintain the system, as well as being left idle in stand-by mode, maybe that meant the the Vaults weren't working to prevent certain planetary conditions from reasserting themselves (such as extreme temperature ranges)?

I think so, yes. I think without someone there (besides the bots) to watch over the Remnant sites, or without an active connection to Meridian*, they've gone dormant/been shut off/having a error message (Eos, Elaaden, Voeld, Havral), or have been broken (like the one on Habitat 7 and possibly the one on H-047c) so those planets that they were shut off have reverted to how they were before the Remnant began terraforming them . Ryder and SAM turn the vault back on so it jump starts the terraforming tech again.

*Them not being connected to Meridian would explain why Aya, even with a fully functioning vault, is still partially a giant volcano.

So is Aya supposed to eventually become almost mostly safe or will the angara always be forced to share their time on it

I'm very surprised we actually couldn't return to H7, at least even in a Normandy memorial sense at the very least. It's the coming of age junction for our character, it could have been a great point of reflection and also allowed us to define the character in quite a meaningful way.

You get the memorial scene sort of in returning th H7 when you reach 100% viability on all outposts.

I've got a 100 in all of them, but I don't see the option to return.

I don't even understand why they would have left it there in the first place since the shuttle was right at that spot for evac.  Who knows what vile things the kett probably have done to his body.  Makes me think back to when we find Cailan's body and what the darkspawn had done to it.

I found it odd that Ryder doesn't ask to see his/her father's body. I know I wanted my Ryder to see his body. When Ryder asks Caryle how dad died, he says "like a hero". Hmm. Death by like a hero. Alec Ryder. Dead. Cause of death, like a hero. 

I agree it is suspicious that no one will give you details about his death, nor was there any sort of funeral or goodby scene or ANYTHING marking his death. If it was just oversight, it was a damn big one.