haha. My marin is awesome! I will attempt to forgive you and not take offense on behalf of it. It's not bottom of the line, it came with shimano wheels and a carbon fiber crankset. I think cranks & wheels are usually made by a 3rd party on bikes.

I'm not sure what you mean by tilt the crankset - as in, the bottom bracket twists or just the crank arm flexes... if that's a problem with the bike or the frame. If it's the crank that's flexing, that's easily upgradeable and that's why a lot of people upgrade their cranks - ultegra cranks are stiffer than 105, and dura ace or carbon cranks stiffer than that. I can't say that I notice a difference, but I've read threads where they compare shimano 105 cranks to noodles. It just depends on your leg strength and how much power you have and I apparently don't have enough to notice 105 cranks as noodles.

If the entire bottom bracket is flexing or tilting and it's the frame - he may need a bike with one of those massive tubes on the bottom bracket

As for wheels - I do see those complaints fairly common on wheel reviews across the net - light people loving such & such wheel vs. heavier guys hating them. He should maybe look into a touring set or something for cyclocross.