What I usually do when I'm bombing is just autolevel, calibrate at some point, note the airspeed in the bombsight that it's calibrated to, and then when I'm close to target just move the throttle to match the TAS showing in the bombsight. Seems to work just fine, about the simplest thing in the game to do. A couple feet high/low or a couple mph off on the speed moves the impact point a couple feet on the ground. IMO unless you're at ludicrous alt it's not worth that much to micromanage your alt/speed.
Seems to me autolevel does what it says on the tin, and you can adjust it with throttle. Setting speed keeps you at a consistant IAS for climbing, which seems to me it would be preferable rather than having a setting that holds to climb rate or something like that.
Wiley.