I like to target my enemy ships as soon as my planes reach altitude (TBs). That way, they drop down to sea level and I can use the ' key to return to ship (at 0 altitude) and then redirect them to the enemy for manual bombing. Most often I'll just target any ship in my sights, not necessarily my intended target. It's a lot quicker to drop down to 0 level than using the decend button manually. Also, by targeting them early, I can focus on reloading more planes while my bombers are enroute to the enemy line.
I even like to mark my enemy ships so they begin to worry and stress out, dodging and weaving (to little effect), and getting distracted. I'll then pop back up and dive back down gettting them to dodge and weave some more, causing them to lose concentration on shelling my team's ships, then I'll unload the torps if on target or go manual and spin around and slam their mid-sections with full effect.
Plenty of times when they are dodging and weaving, my team's BBs will hammer them, as they're distraction and fear from measly TBs is too much for them to handle.
But as the suggestion says, I recommend that enemy ships not be presented with the red marker because it is an unfair advantage for the enemy. That red marker should only be visible to me or my team.
As for the supposed incentive...that's pretty insignificant and certainly doesn't result in an increased amount of damage. Also, manual torping is hampered when a smoke bomb is used, whereas auto-bombing with TBs remain locked on.
