I don't know.
I don't know.
If you get your press to 300, your arms will probably be pretty big.
I'm sure Kali Muscle and Rich Piano know better. The best natty bb in the universe.
I hear a lot of good things about heavy barbell curls, whether straight or EZ bar. I've noticed since adding them to my own training for fun a few weeks ago that I finish the last 1/4 of chinup reps a lot stronger; it's getting much easier to touch my chest to the crossbar now. That could also be caused by doing the chins themselves but it's been too sudden of an improvement for me to think so. I program them in the same sense as everything else: 2 - 3 sets of 5 reps after my deadlifts, 1lb increase each workout.
Make sure to do them inside of a rack so that the rest of the gym will watch you (audience-induced performance gainz).
The point of the podcast is that your arms will grow anyway, along with everything else.
I have big arms and a good bench. My experience is that training arms every day does nothing to impact my recovery for bench pressing 3 times a week on sheiko style programming. I have a large work capacity for upperbody so YMMV. Perhaps try adding in 3x20 for tri's/bi's on each upper body day and then incrementally add more. I pretty much can do the same wrt upper back as well (lat pulls, krock rows etc...)
*note* - I also thing it's important to mention that I never go to failure on these exercises. If I did, I think my recovery story would be different.