12 day old feeding concerns

Hi everyone sorry for the long post,

I am new to the group, and new to breastfeeding. This is my 3rd child, but the 1st one I am committing to with breastmilk. I have an extremely fast flow, and to the best I can explain it a water fountain let down. My breasts stopped feeling extremely engorged yesterday morning, and they are now soft and comfortable but still fill up. I was actually nervous yesterday that I had lost my milk supply because they were so soft and normal so I did pump 3 ounces out on both sides in 4 minutes an the 3rd lowest suction. My breasts are still soft but still flowing like crazy. I do not think that's going to change, and little one eats anywhere within 5-8 minutes on one side and is then full until next feed on the opposite breast. My concern is that is not enough time to feed? Everyone keeps telling me he should be eating for 15 minutes on each breast. With 3 ounces on both sides though, his tummy is too small. He isn't fussy in between feedings unless he is gassy which is noticeable by burps, poop, or belly scrunches. And he poops and pees more than the recommended amount for breast fed babies. Normal yellow mush. He also seems to be annoyed now that my breasts are not engorged with latching because they are so soft. I have to hold my breast for it to be hard like for him to latch. I know he is getting it because he gulps, and even chokes sometimes even if I am in the laid back position. I guess I am just nervous & contradicting myself. In short:

Is his feed time long enough if he is pooping and peeing normal, and not accepting more?

How do I get over his annoyance with the softer breasts & latching?

Is it okay to occasionally pump to check my supply, or will that mess up the supply/demand & re engorge me?

Finally, I was told my milk is drying out because it is too soon for my breasts to regulate. They are still full, and thriving though..

Help, a breastmilk newbie 🤦‍♀️🤦‍♀️