Guys, I am contemplating a 7000 EQM MR to get me to 1K (posted for tips in the MR forum). However, I need your help assessing the following scenario, and I though this was the most appropriate forum to post in.

I am going to travel to either NRT or OSA from ORD in November in business class. I'll book the ticket through my company's travel agent. After the trip to Japan and a couple other planned domestic trips, I'll have 93056 EQM. That already figures in the 150% EQM for business class.

If I can get the Maximizer miles for 7.5 cents or less per EQM ($~525) on the way to Japan (won't need it on the way back if I can purchase an equal amount of actual flown miles), I can live with that since I won't need to do a MR. I just want to make sure I have the mechanics right on all of this.

Right now, my Mileage Plus and OnePass accounts are not linked, and I have 0 miles in my OP account (since it is brand new).

My questions are:
1. Do I need to leave my MP and OP accounts unlinked until I complete this trip?
2. Do I need to book a Continental itinerary (rather than a United one) and assign it to my newly-created OnePass account to be able to purchase "Maximizer" miles, or can I book a United trip and somehow log-in through my One Pass account?
3. Is there anything else I need to consider here? Like, is there a complication for buying Maximizer miles when traveling in business class or anything else?
4. What would you do here?

Thanks so much!