Iphone 4s damaged by OS 8.3?

My Iphone 4s, upgraded recently to OS 8.3, lost its ability to access bluetooth or wifi. Wifi was grayed out and bluetooth had a spinning wheel rather than a switch. My phone was pretty old (3 years?) and the battery was complaining. I spent an hour with an apple person on chat and went through all the possible software fixes and the technician concluded that it was a hardware problem and would need to spend time at Apple. I had a genius bar appointment for Tuesday to have them send it in. I talked with a local non Apple technician about repairing the problem and he said it would need a logic board replacement and this was happening to a lot of the 4's.

Since the battery AND the logic board were both going to need to be replaced I figured I would just buy a new 4s, and I did. Now I am wondering if I will be VERY sorry since if this is being caused by the new IOS I am NOT going to have a long experience with this NEW phone.

I also am no totally confident that my "new" phone is really new. How do I access the number of hours and the battery vital stats?

THANKS,

Richard