Can I update my iphone that no longer has service?

I have an iPhone 4s that I bought almost a year ago with Verizon. However, a few months ago I switched back to my old phone, that doesn't have internet, because my cellular phone bill was too high. Although, I was able to use the iPhone 4s like an iPod touch. I used to it take pictures, face time, and everything else. The only thing I can't do it text and call with it, so I just leave it on airplane mode.recently, there was an update for the iPhone and I've been wanting to update it. Although, I'm worried that if I update it, it will be permanently locked and I won't be able to use it unless I connect it with Verizon again. Can anyone tell my what would happen to the iPhone if I update it?

Iphone pictures and transferring?

I was wondering if there's anything that you can plug directly into your iphone (in the charging slot i think) to transfer the pictures onto a usb flash drive? So you don't have to download them onto the computer first, then transfer to the flash drive.

Is my iPhone using data when?

Is my iPhone using data when I have facebook and twitter installed, I'm logged in, but I'm not using them?
Also is iMessage free from iphones to iphone anywhere in the world? And does iMessage use data?
I have limited data, but I'm trying to use Wi-Fi whenever possible to avoid going over my data limit.

How to use a calorie counter app?

I want to keep track of how many calories using an app for an iPhone but I don't know how to get the calorie amounts for food without labels such as home-Cooked meals and school lunches. I'm not fat but I just want to keep track so I don't get fat!

How to unlock a blacklisted iPhone 4?

I bought an iPhone 4 online, wasn't told it was blacklisted however so it doesn't make calls/texts. I have no method of contacting the original owner, so that's out of the question. How can I unlock the phone, or the imei?