David Megginson wrote:

2. I'd prefer to land KPHL 26 for Atlantic Aviation, winds permitting.
Is it easy to get the ILS 26 approach? Once I'm in the Philly Approach
area, how will they be likely to route or vector me onto the approach?
How do they normally handle low-level, slow (Cherokee) IFR arrivals from
the north?

PHL has a website (www.phl.org).
Look at the Flight Information tab.
I am amazed to see that aircarrier operations don't really commence
operations until 1030 ET! With the exception of one flight at 0630, it
looks like you can get in or out without delay.