Is it safe to give out my DNS?

So I was told about how to improve my internet speed, but the guys wants my DNS from my iPhone or something. Is it safe to give it out?

I brought an iPhone 5S on Ebay and it hasn't been delivered?

Someone was selling a brand new iPhone on eBay for £300, I brought it via PayPal and the estimated delivery time was 2 weeks ago. I've messaged and e-mailed the seller but they are ignoring me - I'm thinking it's a scam now.
Will I get my money back if I do not get the phone?
Will they get in trouble for scamming through the police etc? What will happen to them?

How to recover deleted text messages from iPhone 6?

I just deleted some text messages on my iPhone 6. I think I don't have any backup files both from iTunes and iCloud for 2 weeks. The text messages I deleted are new. So is there any way to get my text messages back?

My iphone won't turn on. Is it completely dead?

My iphone 4s was getting really hot when i used it for a longer period.
one morning when i woke up it was really hot and didn't turn on. I let it cool down and then i kept trying to open it but it didn't work. I also tried to hard reset it (home+lock button). Nothing happened. Yesterday i replaced it's battery with a new one. Still doesn't open. What can i do? I have a lot of data in it that was not backed up and i need it. Can i fix it?

Is 1GB enough for an iPhone 6?

So I want to start a plan with Verizon and right now 1GB is looking like the best for me, money wise. I usually have Wi-Fi and when I don't I'm not really on my phone much. The only things I mainly use it for while not being on Wi-Fi is google maps for the navigation while I'm driving somewhere new & I just recently moved to a new area so might be using that a lot and every now and then snapchat lol so just wondering if 1GB seems like enough?

Is it common to bring dslr cameras to study abroad?

I'm going abroad in the fall for a semester and I was wondering it if was worth buying a dslr camera. I own an iphone 5 and a point-and-shoot camera that works okay but the sometimes takes blurry photos.

Is it worth buying a $400 dslr camera?

Is it common for students to bring dslr cameras while studying abroad or is it too clunky?

Added (1). btw I'm in college