First of all i would like to say hi to everybody, im a new android user and i would love that everyone that can help me could explain things very well otherwise i wont understand a thing xD
Also, english is not my main language so mind the gramatic mistakes
Now into the problem:

My sister received a Xperia X10i from my father and it's all messed up... My dad is not the best person to use a smartphone so I need help fixing it up for her. Im used to my blackberry so my idea on what would be the best for the phone was:
(im not sure if you can do this, im adapting the backberry procedure to android)

-Wipe the phone to it's "paper weight" state: Completely remove software, clean the phone without leaving any piece of android.

-Load updated os: Right now it's running os 1.6 (wich sucks) and whenever i try to root it i cant... it bugs out and the aplication stops (tried both rooting exploits) So i though that maybe loading os 2.3.3/the latest in the phone would fix that

-Rooting: It's always good...

-Flashing a custom rom

-Wiping device again(? clean it, root it, and then load a custom os with OS4 or 3... , anywhy try to load the latest os possible so that it would run smooth/faster

-Install everything with the changed rom...

Can i do this? do you know how to fully hard clean the phone?

 

Hmmm but it's not that what i really wanted... i wanted to know if i can wipe the phone of EVERYTHING!!! kinda like cleaning the rom too... Then installing everything again..can i do that?