Re: Need advice on how to get started with my goals
You'll be using an ILBE pack at boot camp. There are a few other pack designs in the works because the ILBE is near-worthless and has lots of flaws, but that's the standard issue pack for boot camp and fleet units these days.
As for packing it, yeah you'll have to do it like your DIs say, but generally you want heavy stuff at the bottom of it.
Your run times are going to put you in the top 5% of recruits, actually probably in the top 5% of Marines in general. Spend some time getting bigger and stronger--as long as you keep doing some conditioning, you can get bigger and stronger without ruining your run time. But cutting back on some of the endurance work will probably be necessary for you to make much progress. Find someone experienced who can help teach you the lifts if you're worried about form.