resetting my android to factory settings?


Okay so I have a few questions, please answer them all if you can.
Firstly, I have a Samsung galaxy Y rooted.

Now, I want to reset my phone but I want to keep it rooted is that possible?

Also I know that there are two ways to reset. One is from a setting option that says reset phone to factory settings and the other is to turn your phone on by holding the home button and the power and the volume up buttons at one go. Then choosingthe option to reset it there. Is there any differencein the way the phone is rested??

Lastly my phone is unlocked so I can use any sim card. Will the phone be locked againif I chooseto reset the phone? That's all thanks!