Rereading apostles it occured to me. About a quarter of the way in, there is a long lecture to Tom about why Gods can't enter the Abyss without spdisturbing some treaty or balance thingy. and yet there Phestus, Usiris, and Bess, clearly in the Abyss.

Another question... I presume that with your cross referencing different books Sir Samwell might be the alias of a certain Samwise Gamgee?

The key trick on the balance is gods can come, if invited/no one complains.

So:

1) Bess & the Outpost are a clear violation, however, only Tom and friends know this. The other gods believe the Nyjyr Ennead to be dead/missing/AWOL.
2) Sentir Fallon would be a problem, except he was invited by Lilith, or has been at times. Since Lilith (and/or Sammael) are sort of the de-facto rulers, if they don't tell anyone, it's fine. It's actually a far bigger problem for Sentir, that he is working with Lilith than the that he's in the Abyss.
3) Phaestus, Volund, Loki, Singkun & others were/are Orcus' guests, arguably his Court. He invited them. Those who are aware of Tartarus are generally aware of their connection.
4) Technically an Olympian in the Abyss (Orcus) would be a problem, but he's been there for millions of years and most people don't get the connection (do not know he's a god) and consider him a permanent resident, and as one of the Princes of the Courts of Chaos, he was considered part of that signatory group. I.e. he got grandfathered in. This is true of a few other gods that live in the Abyss, he is not actually the only one. What is true, however, is that none of the gods living there have access to their god pools (if they have one)

Yes, they would be cut off from their godpools in the Abyss.

In fact, in book II, Sekhmekt mentions this while watching Phaestus work on a big gun.

They closed down their main/obvious outer planes. That doesn't mean they don't have a hidden plane or something with god pools on it.

Based on what Sekhmekt has said, we have to assume the GP's and PP's aren't on Uropia since she can't access them.

Blow her cover, probably.

As far as god pools on the material planes, well, to be honest, Singkun and I were pretty wasted when the rest were talking about godpools yada yada. There's something rather tricky about them being on the material planes, but I don't remember what it is. I mean, I think you can have them, but they are less stable or something like that...like I said, we really were not paying attention to that stuff when they were discussing it.

What if it's like a water bed and suddenly springs a leak?

Nearby mortals would be soaked in mana, and nothing brings "monsters" (a pejorative term if I ever heard one) faster than that!

Yes, but it is funny!

I don't do windows, floors, ceilings, walls, carpets or dishes.

I'm naked, Buck Naked, that's my pseudonym.

So...no!

Except for the fancy buggers with too much money to burn.