Hard case or silicon for iPhone 4s?

I have a question, i bought a apple 4s this last month and i'm wondering which is the best case to protect against dropping, dirt and etc. Is it hard case or a silicon one?

Why are my texts so delayed with one person?

I have an iPhone 4 with tmobile and she has an iPhone 4s with sprint. And the texts are like an hour late or I just don't get them at all. I don't know how to fix the problem we've both restarted our phones. My conversations with other people are working just fine but between me and her it's not working.

Is it safe to provide IMEI to carrier for unlocking iphone?

Hey guys i borrowed iphone from an unknown dealer online and i don't have any information about them. Now i want to unlock my iphone to use it on any carrier.
Is it safe to provide them my imei? I'm using gevey till date and worried that they will stop this trick i tell them my imei,
Also if they agree to unlock, should i pay them?

How to stop getting text notifications?

So on my iphone i did this thing where you get a notification every time a friend that you chose on facebook posts anything. So of course all my friends post a stupid status every 2 minutes and i didn't know how make it stop so i just unfriended them. Does anyone know how i remove the friends in the notififcation list but keep them as friends?

Give me some advice and constructive criticism on my photos?

I'm not a professional by any means. I only use an iPhone 4S (not really interested in getting one right now) and do any editing using Camera+ and Snapseed. I want to take good pictures, and have recently been reading more about things like composition. I feel that a lot of the pictures I have taken thus far are very amateur and without much thought or feeling.

Can you give me some feedback on my pictures? To me, giving me constructive tips on how to get better (tell me what you like and what you don't like about a photo) would really help rather than just saying "these photos suck" or "these photos are awesome". I appreciate the help! Here is the link for my photos:

Finally, what are your thoughts on using an iPhone 4S for pictures? Should I be investing more money on an camera, or is an iPhone "good enough"?

Added (1). When I said not really interested in getting one right now, I was referring to an actual camera

Are electrical outlets different in Vietnam?

I'm going to Vietnam and staying with family. I'm wondering if I'll be able to charge an iPhone with a regular two prong plug. I don't know anything about this, really.

Would I need a universal charger or anything?

How to activate voicemail on an Iphone 3gs? - 1

I keep getting calls from Unknown, and its called me so often i'm starting to wonder if its important, i don't want to answer, if it is important they can leave me a voice message, but i never get voicemails so i was thinking maybe its not activated
how do i activate it?

Added (1). Is this english or were you speaking another language?