How to turn iMessage off for a contact?

My friend just got a new non-Apple phone, and I can't seem to send her texts cause she previously had an iPhone. I've tried changing the 'type' of phone and even deleting her contact but nothing seems to work.

How to delete iPhone photos on a Mac?

I connected my iPhone to the USB of my Mac and I have gone on image capture and itunes and there's nowhere that I can delete the pictures off of my iphone on my Mac. It just gives options to import them. What do I do to delete them off of my iphone from my computer?

NMAP scan shows hosts which are not in my LAN? How is it possible?

I used nmap -sP (also with -PA and PR), and it shows 8 hosts up in my network. I know that only 3 hosts are up. How are this possible? One of the hosts it shows is iphone. I don't have iphone at home. Can it be a friend's iphone, who visited us a week ago, still in the router? Or could it be a neighbours ip address. It's private address anyway (192.168.1.x), so I suppose nmap can pick it up from a neighbour.

Any clarification on this issue would be much appreciated.

Is it possible to write an iphone app that syncs to vehicles?

I have an idea for an app but for it to work it would have to know when the owners vehicle was on and off. Obviously this would only work with newer cars but I didn't know if it was possible to create such of an app with sync capabilities.

Thanks

Added (1). P.S if it is possible does anyone know how/a website telling how to build such of an app? I've had no luck myself but don't know exactly what I'm looking for.

Can I just change to an iPhone?

Currently using a Sony M2. If I buy an iPhone (a friend is selling his iPhone 5) would my micro sim be compatible? The phone is unlocked.
My current contract has a year to run.

Forgotten touch ID and pass code?

My friend played a prank on me, she locked my phone and change my touch ID on my iPhone 6. Asked her what's the pass code but she forgot she was to "DRUNK" to remember ugh! So since I didn't have a computer I had to use my friends iTunes to restore but unfortunately I can't use it because it requires my touch ID. I don't know what to I tried taking in and it cost me allot to JUST GET A NEW IPHONE because they can't unlock my iPhone 6 unless I call apple store. Please help I used the iTunes and the wire that comes for my iPhone to restore my iPhone but I can't do anything any suggestions please.