Is data connected to the sim card? (Verizon)?

I'm planning to travel to China and replace the sim card on an IPhone 5s with a local one, and I want to know once I do this, will the phone only use data from the local sim card?
e.g. Is a certain carrier's data only associated with the sim card and once you take it out, you can't use their data anymore?

If you buy something from someone can they take it back?

So my dad sold me an iphone 5s for $30… & everytime he gets mad he says "i'm gonna take the phone back" & i say "you can't because i bought if from you" & then he says "ill give you your 30 bucks back". Can he do that legally? Because i bought the phone and he does not pay the phone bill

My IPhone 5 screen is extremely laggy?

After about 30 seconds into using it, it starts to do its own thing. I've tried restarting it several times and nothing has changed. For example, when I'm at my homescreen and I click on the App Store, it clicks on settings, when I scroll up in an app, it scrolls down.

What do you guys think of my raps?

So i recorded it on an iPhone sorry audio quality isn't 100%. So my friends tell me I'm pretty good at this stuff, but they're my friends so ya know lol. I wanted to know some unbiased opinions about what you guys think of my rapping skills. I've been doing it as a hobby for a while. Here's a cover interpretation of drake/lil Wayne's "she will" with a freestyle at the end. Second one was for my (ex) girlfriend. Lemme know what you think honestly.

http://www.smule.com/p/255512114_80693605

https://soundcloud.com/...ne-special

Can't upgrade AT&T iphone with next program

I'm unable to upgrade my Phone through the next program with trade in because for some reason my phone on the account is listed as an iPhone 5s 16gb space grey, but That is not the phone I've ever had. I've always had the 32gb 5s silver.

How to check for MMS messages without turning on data? (iPhone)?

I have a limited amount of data, so I try to keep it off when I'm not using it. Of course, this means that when a friend sends me a picture message, I won't get it until I turn on my data, sometimes weeks later. Is there some way to set up a notification saying that "hey, you have a message coming in. Turn on your data" or something to that effect? I feel bad when I just ignore my friends, but I don't have the data to waste.

What is the proper way to charge your iPhone?

What is the proper way to charge your phone? Should it be done over night? Do I have to wait for the phone to die before I plug it in? Do I have to unplug it a few minutes after it hits 100% or it could stay for longer? Obviously I want it to last at least a whole day(daytime) so about 15 hours maybe? Also my phone is new it has only been charged once since I bought it from the store.