Yeah that's open to misinterpretation, mainly 'whenever you possibly can' -- I meant 'if you can reasonably risk it, get yourself in some degree of trouble.' You really can't sit around healing up that long, or anything -- Xom is likely to do something unpleasant when you do (doesn't matter so much by endgame, but by then you've probably switched to another god). OTOH when you are in danger, he's likely to do something pleasant (in particular, I'm looking at 'good mutations' here as something that improves your survival chances and allows you to continue calculatedly endangering yourself).
So I guess I'm saying that danger is less dangerous than Xom, in the early game and midgame.
Many of the Xom effects --- confusion, inner flame, sudden mutation with torment level damage --- are undoubtedly worse with monsters around.
That's true.
running between fights at 40% hp
That is not playing, that is suiciding. I'm talking about running between fights at 75% HP. If your HP at the end of a typical fight is 40%, I also call that a suicidal playstyle.