Iphone 5 flickering after dropped in water?

So I dropped my iPhone 5 in the toilet for about 2 seconds before I took it out. I immediately dried it out with a towel and submerged it in uncooked rice for 36 hours. On the 36th hour, I turned my phone on and it worked! Yay!

However, I noticed there's a little damage to the screen, but it's just a barely visible line. You can only see it if you tilt your head.

After about a minute of it being on though, my screen started to flicker and the touch screen was pausing. So I decided to turn it off again. As it was shutting down, the screen was flickering to the left side and I started panicking. It finally turned off and now I put it back in the rice.

Please tell me why the screen is flickering and if I can still fix it! I'm in a major panic. I really need help with the please. What can I do?

Can I use my iPhone 5 on any service?

I bought a iPhone 5 last summer at best buy on my Verizon service. Well due to financial reasons I decided to terminate my contract and switch to Virgin Mobile. I got an android because it was cheap but I defiantly miss my iPhone. Today I was playing around with my old iPhone found a sim tray. Opened it and behold a verizon SIM card. I didn't know they had SIM cards! Anyway since my 4g virgin mobile phone came with a SIM card… If I swapped them do you think I could get service on my iPhone. It seems like it's unlocked.

Can I charger my iPhone without a charger?

So I have an iPhone 3g and an iPhone 4 that are both completely dead and both the chargers are broken its late at night so I can't go but another is there any way I can charger either of them with out my charger?

How to chance my passcode on my iphone?

I've already done this multiple times before. I change my passcode every so often because I don't like people being on my phone. But today I wanted to change my passcode so I went to settings then general, and I couldn't find the setting were you change the passcode. There's usually "auto lock" then under it "passcode lock" then under that "restrictions", but my phone does not have "passcode lock" for some reason and I don't know why. I have an iPhone 4s just so you know and I just updated it to iOS 7.1 yesterday.

How to set up a vpn on my iOS 5?

I have an iPhone 4S and I haven't updated it so I guess it's in iOS 5? 4? I don't know. But anyways for school I wanted to use Vpn to unblock some websites and apps that I use but it won't let me set it up and it's really annoying. It just won't connect. I don't know if I'm putting in the information wrong and I've watched many videos on YouTube and I'm doing nothing wrong. If anyone could help me, Please AND Thanks

IPhone 3GS won't be detected by windows?

I bought and used iPhone 3GS from a friend, but when I turned it on, there's a message that says "iPhone is disabled, connect to iTunes", with the only thing that you can do is emergency call. It also shows a message on the top corner that says NO SIM, I tried to restore it holding the power and home button, but it only shows an image with the iTunes icon and a USB cable. Please help!

Added (1). iTunes does not detect the iPhone either.