For this scenario, I would simply record you to your audio track(s) and the friend to their audio track(s) and send both to an aux track for a touch of reverb while tracking. (and remember that sometimes, feeding aux tracks to aux tracks can make a mess of ADC)
There is no "right" or "wrong" here, but...just because you CAN do something, doesn't mean you SHOULD
I've been recording for a long time and still just record vocals to audio tracks. Now those tracks will have sends that feed aux tracks for reverb and echo, but I never feed echo back to headphones(it tends to mess with a singer's timing). My audio tracks will have the following plugins in place while tracking: EQ III(set for hi-pass)>BF76(gentle compression at 4:1)>SMACK!(warm optical compression)>Pultec EQ1A(adding "air" at 10K). These 4 plugins only add 1 sample of latency(at mixdown, I swap the Bomb Factory Pultec for the Waves Puigtech that sounds "better" to my ears, but has a bit of latency).
As for separate tracks for verse, chorus and bridge, the only time I record it to separate tracks is if there is overlap between parts, or if I need to deal with a wide dynamics issue(like the singer whispers he verse but belts the chorus out). In most cases, I will simply ride the preamp gain, but recording separate tracks is a perfectly useful solution.
When it comes time to mix, I usually stay with a single track throughout with a second track for doubles in the choruses. A 3rd track for adlibs works fine, but I only do that if there isn't space on the main vocal(I like having all of the "lead" vocal on 1 track whenever possible).
Some people use the aux track with effects as a way to print everything(routing the aux track to an audio track), but I don't see the need(of course, YMMV)
