MS won't buy Xamarin unless someone else is planning to buy it. They probably have some sort of exclusive agreement to give MS priority when buying. It is simply cheaper for MS to let Xamarin run itself than to take it under the wing of MS.
Just listen to your body, if the weight is too much remove, if the reps are too many take your time or do less. If you want to show off or feel peer pressure then you shouldn't be crossfitting. I am doing CrossFit for the last 6 months and I always stop when I feel uncomfortable or in danger.