First let me answer you first question. The only problem about BTC is that it changes it's range or currency but no one knows when. But I recommend you to save your BTC cause you know it might hit a high rate someday. Second, if your problem is changing your BTC address, you can create another wallet account so that you can have another BTC address. Then go to your profile, click forums profile information. You can see a box there for your BTC address then you just need to replace your old BTC address of your new one then save it and you're done.