... I have more concern over getting some point cards and adding them, and not being sure if that original 50 was being used for content and have it all of a sudden disappear a year from now.
I don't think Microsoft is as evil as credit card companies

Reminds me of the old CC scam:
Cash advance rate of 21% while you're at your introductory purchase rate of 1.9%.
Charge $500 of purchases and do a $100 cash advance.
Make payments of $100 monthly and it goes towards the 1.9% until there's nothing left but the 21% cash advance to pay.
Keep making new purchases and never pay off the 21% eating away at the back end.
They've been properly sued or otherwise taken care of, but some still exist. New law is pretty much anything past the minimum payment goes towards the highest interest now.
There's a way to actually check on the expiration dates, if applicable, of your points. They've always had that implemented in the system but didn't really enforce it. Same with expiration dates on Gold trial codes.\\
Best way to avoid it would be to simply hold onto any new point cards until you use up your current reserve. Ever since my account was FIFA-hacked, I never store excess points just in case something bad/dumb happens.
7TH: since you're a beta guinea pig, you should be able to look at your moneys in your account and have it show you when specific amounts will be expiring. I think the Bing thing (and some losing all of their points) was just the fault of it being Beta. Sometimes I wonder if people realize that Alpha/Beta are meant to work out the things that can (and will) go wrong rather than just early access...