How to change iCloud info on an iPhone 4?

I just updated to iOS7 and i need to put in my iCloud information. I recently changed the email I use for it but my phone didn't recognize the change and it won't let you edit it on the phone. I tried to delete the account to start over, but every time I try to delete it a pop up says I have to enter my password to turn off Find My Phone, but I can't get the password right because the email in there's wrong and you can't change it. So frustrating

IPhone 4 8gb problem! No more space?

Okay, so I have the iPhone 4 and I was so excited to update to iOS 7.It says I need 3.7 gb to update. I deleted everything up like 20 photos that take up 174 mb. I need.4 more gb to update. But, there's nothing left to delete! It says I have 3 gb being used but there I nothing to be deleted. I have the iPhone 4 8gb btw. Please someone help me!

IOS 7 problem! What is in the bottom right corner of my screen?

I downloaded IOS 7 on my iphone 5 and if you look in the picture in linked, there's a dark greyish box on the bottom right corner of the screen, and when i press it, two blue arrows pop up as you can see. This is really annoying and I want to know:
1.is this supposed to be there? (I haven't seen anyone else with this)
2. How do i get rid of it?

here is the link to see my screen:
IOS 7 problem What is in the bottom right corner of my screen

Why can't I update to iOS 7?

I have an iPhone 4 and it said at around 3PM that I could update when I had Wi-Fi so when I got home, I went to update it and the update didn't show up (7PM)!

How does the iPhone bill work exactly?

My family has the family plan on verizon wireless and I was wondering what would happen if I were to replace my flip phone with an iphone 5c. How much would the price go up? Would it just be the $30 (or so) for the data or does the iphone make you pay a ton more just for it being an iphone?

My iPhone won't let me delete my photos?

I just downloaded the iOS 7.0 update on my iPhone 4. I imported the photos from my iPhone onto my computer before the update. Then after the update I put them back onto my phone, but decided I wanted to delete some of them. When I tried deleting them(off my phone), there was no option to do so. So now I have 900+ pictures on my phone that I don't want. Please don't tell me to put them in a separate folder bc it's not that I'm concerned about, I just don't want them taking up so much space, and now I can't delete them.

Is IOS 7 Good Quality? IOS 7 Users Please

I'm currently backing up my iPhone onto iCloud. I want to know if IOS 7 is any good. Does it have great quality? Did everything transition correctly? I want to know before I upgrade. I know I can't downgrade so that is why I want to know before I do the transition on my phone.