Not really important imo which way round, or whether you do one or either or neither or both. Fork is definitely less bike-specific, I put a DHX in my old Hemlock and it was a blobby fiasco but the Lyriks ruled in it
Dunno. I found a coil fork too linear for what I like to do, with around 20% sag it’d nearly bottom out when I bunny hopped up kerbs. Back to air for me. If I had a bike that just pointed downhill (a downhill bike, maybe? 😆 ) I’d have a coil fork on it, but not for generally buggering about on a Swiss army bike (BFe).
Depends on how progressive the rear is, a simple coil fork can be unbalanced with a highly progressive rear leverage ratio coupled with an air shock. Coil forks can unbalance the bikes on jumps etc.
Unless you are getting a coil fork with some kind of end stroke ramp up – eg PUSH ACS-3, MRP or an open bath cartridge with a hydraulic bottom out or the ability to adjust damper progression by altering oil volume.