When should I stop auto-explore?

In Brogue, I like to auto-explore the first level, as it's always very easy and not really dangerous and stop when I get to the second level, exploring it on my own from there on, as auto-explore doesn't pick up all the items, will sometimes not attack sleeping enemies (free XP!) and will not kill Bloaters from a distance (which as you all know, spells out your DOOM in capital letters).

Am I being too careful? How deep should I let it auto-explore? Should I even use auto-explore at all?

I auto-explore a lot in the first levels and use it less and less as I get deeper (only reached 16 depth, so take advice with caution).

Of course the problem is to identify threat, so my usual method is to auto-explore until I find an enemy, then I try to deal with it (darting a bloat, killing a sleeping enemy or letting a wandering jackal go) and when I feel the situation is safe I auto-explore again.

As you get deeper, additional threats like traps or invisible enemies (damn you phantom at level 16!) make auto-exploring more dangerous.