Should I buy an iphone 6 wallet case or a regular one?

I've been thinking about switching to a wallet case for the iphone 6 since you can carry cards and money right with your phone plus you can prop it up on a kickstand. However the case wil make the phone much thicker and hard to use casually. Is it worth the trade off to get a wallet case or just stick with a regular slim fit case?

Should I buy an iPhone 6 Plus in the US and take it back to the UK?

My friend is a pilot and goes to America a lot, I was wondering about asking him to buy me an iPhone 6 Plus over I the US and bring it back for me as it is cheaper over there (disregarding tax). Will the iPhone work in the UK? Will she have to pay tax when taking it over? I already have a sim that I use in my iPhone 4s, will I need a new one? I'm assuming that the size for a sim has been reduced aswell.

I want to buy an iphone 4s but I don't know anything about them and I don't want to get ripped off?

I found someone selling an iPhone 4s and he says it has Automatic Gevey. Can someone explain to me what that is? I'm currently living in Romania and my carrier is Orange. He said it has Automatic Gevey preferably with Orange. What does that mean? I told him I'm going back to America and would like to know where the phone was bought or what country it is coded so I know what to do with the unlocking and stuff. All he said back was that it's from England and Vodafone carrier. He also stated it has the newest software, ios 7.1.1, is it the newest? Sorry lol… I'm a total iPhone noob, I always had Androids. I'm just very anxious because my friend bought a 3GS apparently from the US from at&t and it was jailbroken I guess? He reset it and it didn't work after that and I really don't want something like this happening.

Is pencil lead harmful to the inside of an iPhone?

Is pencil lead harmful to the inside of an iPhone?

Added (1). The reason I ask is because I have an unlocked iPhone 3GS. It was given to me by a friend who upgraded to a Samsung Galaxy. However, I was pretty stubborn as to use a #2 mechanical pencil and got a small piece of pencil lead stuck in the phone. Is this harmful to the phone? Should I be worried? It's a nice phone, and I don't want it to fry. I can't afford a new phone right now.

Why doesn't my iPhone keep all of my mail?

I have 2 mail accounts on my iPhone; my Gmail and my exchange. My gmail account keeps emails from way back… I'm talking 2 years and more unless of course I delete them. However my exchange email account will only keep 20 emails and then will just auto delete the one at the bottom. It doesn't go into the delete box, it just vanishes! I have my settings set to manual fetch and have also set the email settings to unlimited emails for both accounts so why would my exchange email be doing this?

Some help would be much appreciated.