Yep. Section 6.1.8 of the 2020 Operations Manual:
Players on the COVID_19 Related IL will not count against a Club's Active List limit, Reserve List limit, or against the Club Player Pool limit.
Probably not. Again from Section 6.1.8:
In the event that a Club experiences a significant number of COVID-19 Related IL placements at the Alternate Training Site at any one time (i.e., three or more players), and the Club chooses to substitute those players from within the Club's organization, MLB reserves the right to allow that Club to remove those substitute players from the Club Player Pool without requiring a release.
This language indicates that, under the specified circumstances, players who are added to the Pool to replace players at the Alternate Training Site may (at MLB's discretion) subsequently be removed from the Pool without requiring a release. But there is no such stipulation regarding players on the Active List.
Now, the Phillies could, in theory, assign Kingery, Hunter, Neris, and Suarez to the "Alternate Training Site" (e.g., pretend they're not core players) to try to get them covered by the above language - but IMHO, that's what "in the discretion of MLB" is about... to quash obvious shenanigans.
We'll see how this plays out.
I assume that you all have completed your homework assignments and read the Operations Manual. There may be a virtual pop quiz at any time, without advance notice. 