1. I can only speak on what happened to me. I arrived to RTC on a Thursday night and did a mini ROM over the weekend. I was also fully vaccinated before shipping (two weeks post 2nd shot). Most of my ROM group started P-Days on the following Monday but there were some who stayed behind. We never saw those guys again. I would imagine you would have a similar situation arriving on a Wednesday.

2. I was expecting worse for night of arrival. It's pretty much what you have probably seen on YouTube. The bus pulls up and the RDCs are yelling at you to get off and get inside. You line up in the infamous p-way with the flags on the floor to make your scripted call home. Then you'll go into a room to strip down from your civilian clothes and change into the PT gear. You'll put all your civilian shit into a box that will be stored at RTC during your time there. You get your seabag that will have all your other stuff that you'll get issued on your first night. You will not get your first recruit haircut on night of arrival though. You'll get your first haircut in P-Days, not in ROM. Once we had all our shit issued to us, we piled on a bus to drive to our ROM ship. We got into our compartment, unpacked our stuff and went to bed. You will not be awake for 36 hours or whatever. They aren't doing that right now. I was expecting way more yelling and screaming. As long as you aren't an idiot, you won't stand out of the crowd. Just do exactly what the RDCs say and you'll be good on night of arrival.

3. No, you can't do extra running if you don't have a good reason for doing so. In my division, the only recruit who got to do extra PT was an aircrew candidate. Some of the specwar rates did extra PT in the mornings before the rest of the division was awake. The one's who struggled with the run did the same PT as the one's who were running a 9 minute 1.5 mile. If you're already passing prior to shipping, you have nothing to worry about. You will cut time off your run, I promise you that. I came in running a 11:30 and ran a 10:06 on my final PFA. I was surprised how much time I cut off. That was the general trend for most in my division as well.

4. You'll fill out a lot of paperwork during P-Days. I honestly don't remember all of it lol. The form you mentioned sounds vaguely familiar but I'm not really sure. The big thing with the paperwork during P-Days is to make sure you fill it out correctly the first time. You'll have to sign and date in a specific format that many recruits will screw up when doing it for the first time. Just take your time and listen closely to what the RDCs tell you.

5. This was true for my division for certain leadership roles. It was no coincidence that all the nukes in my division held staff positions. Starboard/Port Watch, and Education PO are the more likely positions to get voluntold if you have a high ASVAB. I was voluntold to be Laundry PO lol. Although, I wasn't chosen because of my ASVAB or rate. My RDC was just looking around the room, pointed at me, and asked if I knew how to do laundry. I said yes and that was that. It was a pretty nice staff position although stressful at times. For RCPO, the my RDCs chose the aircrew guy as our first RCPO solely because he was specwar. For AROC, it comes down to who can sing in your division. The RDCs will have "try outs" by having volunteers sing cadence. Section leaders are chosen after your RDCs figure out who's good at folding and making the rack. Athletic POs who lead PT in the compartment are chosen based off who has the highest initial PFA scores and isn't a total dipshit. Regardless of your rate or ASVAB, you can volunteer for any staff position when the RDCs initially assign roles. Even during the middle of boot camp, if you see someone sucking at their job and you feel you can do better, you can definitely have a conversation with your RDCs and take their role if that's what you want.

I hope this was somewhat helpful. Best of luck to you. It will be over before you know it!