Cast spell, sustain, and then go astral? What happens? Options

[NewtonPulsifer]

I'd love some help and input on a rules question I have.

Rules question #1 - say I cast a physical spell and sustain it. Then I astrally project. Does that spell stay sustained?

#2 Also, what if I cast a mana spell on myself or someone else and sustain it (say a detection spell). Does that stay after the projection?

#3 What about when the spell is sustained by a sustaining focus or spirit? It doesn't seem necessary for a spirit to manifest if using the Spell Sustaining or Spell Binding service, so that might imply that one could cast, sustain, and then go astral (or alternatively, cast while astral, sustain, and then drop back into body).

Here's some source material I scrounged up:

From the faq:

Q: Do you need to maintain line of sight (or touch, with Touch range spells) to sustain a spell? What about Permanent spells?

A: No, once a spell is cast, you do not need to maintain touch or line of sight. You must maintain touch or line of sight when casting a Permanent spell, however, until the spell's effects become permanent.

From pg 184 of 20thAE there is also a limitation on moving the area of an area effect spell while it is sustained:

If an area-effect spell is sustained, the affected area may be moved
with a Complex Action, as long as it remains within line of sight.
Characters who “drop out” of the affected area are no longer affected
by the spell; characters who are “enveloped” by the area must defend
against the effects of the spell as appropriate.

From pg 187

A magician can call upon a spirit for Spell Sustaining in the appropriate
category. While the spirit maintains the spell, the magician
does not suffer any sustaining modifiers for that particular spell. One
service is used up for each period equal to the spirit’s Force in Combat
Turns that it sustains the spell. A Force 3 spirit that owes two services,
for example, can only sustain a spell for 6 Combat Turns. The magician
can take over sustaining the spell as the spirit finishes this service
(or at any time) so that the spell does not end. If a spirit is disrupted or
banished while sustaining a spell, the spell ends.