Anyone want to help with pre-marathon races? (Read 212 times)

I'm running the Ottawa Marathon 27 May 12. I think I'm on track for my goal (<3:00), probably a hair light on the mileage but better trained than I've ever been. Three races have presented themselves:

1. I'm planning on running a ½ marathon 2 weeks before the race (13 May) at roughly marathon pace. I'll probably do some extra easy work as warm up and cool down to make that my last long run. A friend of mine has a goal ½ pace very close to my goal marathon pace, I was pretty much planning on pacing him. This has been in the plan for a while.
2. The 'association' - mostly retired guys from my professional area is holding their charity race a week before that half, a 10K (5 May). I've run this when they've held this race before, and it's worked out quite well. 
3. A team XC event is being held at work on 11 May, 2 days before the half, and my unit's team has been 2nd the last couple years. We've gained a couple runners - might be a chance to win it, plus the whole team morale thing.

So, I've got the 10K 3 weeks out on Saturday, then the XC race (6.2 km) on Friday, then the half on Sunday. I look at this as a lot, but many of my best 'peak' races have been after racing into shape this way. I've never done a marathon before, though.

The half is pretty much a given as a dress rehearsal for the marathon, and practice holding my goal pace.

What should I do with regards to the other two races? Do I race them both? Pick one or the other and race it, pace run the other, or just run both of them as marathon or tempo pace runs? 

Thanks for your opinions.