I mean it is all a matter of personal preference, I don't personally wake babe up once a nap has reached 1.5hrs I just let them sleep. If they are napping a silly long time like 2.5/3hrs then yes I would absolutely wake them.
I would try to resettle after that 5:30/6am feed...you don't want him thinking that's an appropriate time to wake up for the day...because it isn't lol (despite what my DD thinks
)
For the afternoon yes, I would try a nap after maybe 1.15hr A time. Sometimes they look perfectly happy and awake but as soon as you start the wind down routine it becomes pretty obvious how tired they are. My DD will look happy as a clam but as soon as I take her into her room and start putting on her sleep sac you can see her eyes and she's practically nodding off.
Naps should be generally 1.5hrs, I would usually recommend that if they wake after 30 or 45mins to try to resettle the nap. Some babies just fall into their own routine though so if you find that short-long-short works well you can try that, I think though the main thing you are risking is OT so you will find that start to appear near the end as as only 1 nap has been truly "restorative".