First attempt to root.......Please help....!

[Xperia80]

I have a xperia u (ICS 4.0.4) after update to the ICS my phone lags a lot and very slow.So i thought i should flash a JB(4.1 or 4.2) rom.I didn`t do it ,because JB roms have major bugs(camera not working).Soi am happy to stick with ICS.If you know any stable jelly ben rom please tell me.I found that xperia u, firmware version 6.1.1.b.1.100 is more smooth and less bugs ,but it`s not availbale to update via pc companion ,I am sorry that i ask previously ask questions ,i saw a uliwooly`s page about upgrading but  i don`t undstand that becaue this is my first attempt.please answer my questions.My English not good, sorry for that.this is like a exam paper  ,Thank you

current staus------------------>
Sony Xperia U (ST25i)
ICS 4.0.4
Firmware 6.1.1.b.1.54
        (Qustion look simillar but read whole question,put the question number and answer,because it easy to undstand)

1) how to find my phone root or unlocked bootloader(because i buy it from a friend) ?
2) Do i need to unlock my bootloader to flash a new firmware version ?
3) Do i need to unlock my bootloader to install a JB(4.1 or 4....) rom ?
4) what is the most smooth and lees bug sony firmware for xperia u (i found that it is 6.1.1.b.1.100 ,http://www.xperiablog.net/2013/06/22/new-firmware-released-for-xperia-u-6-1-1-b-1-100/) ?

5) Do you know any jelly bean rom for xperia u which is stable and no major bugs ?
6) Can i use sony flash tool to flash my phone (http://developer.sonymobile.com/services/flash-tool/) ?
7) After i flash my phone ,if sony release a new update can i install it via pc companion ?
😎 After unlock the bootloader,,if sony release a new update can i install it via pc companion ?
9) After i flash a new Firmware ,If i want to go back to old firmware ,can i do that ?  

10) After i flash a new Firmware ,If i want to go back to old firmware ,can i do that ?
11) After i flash a Jelly bean rom ,If i want to go back ICS (firmware 6.1.1.b.1.54 ) ,can i do that ?
12) Can i unroot ? can i locked my bootloader if i unlocked ?

[anfer66]

Firmware 6.1.1.b.1.54
ICS,not root and locked bootloader

[devsatan]

Ok . For Unlocking bootloader.

1)First download the firmware kernel 6.1.1.B.1.10.This is for rooting purpose only. Then open flash tool.

2) Swithc off your phone. Plug it out form usb port .

3)Now while holding Volume up button , Click on Unlock bootloader icon in flashtool . It will ask  key for unlocking the bootloader. Put in that key that you received from Sony Corp . and then click on unlock. 

4) Your bootloader is now unlocked.

[anfer66]

It works ,next?

[devsatan]

Where are you from??????

[devsatan]

You would have to root your phone . For that follow the below steps:

1) Download the 6.1.1.B.1.10 firmware. Then place it in c:\Flashtool\firmwares directory.

2) Open flash tool.

3) Then switch off your phone . Connect it while holding Volume down To go into Flashmode Mod. 

4) Click on flash Icon in flashtool then select 6.1.1.B.1.10 firmware and exclude system, cache,data,TA,fota and include kernel and loader.sin files.

5) Then click on flash. This will flash 6.1.1.B.1.10 kernel on your phone.

6) Switch on your phone.

3) Enable USB debugging on to your phone .

4) Connect you phone to PC while it is in switched on state.

5) Click on root button in flashtool and procedure will start .  

6) You could see the restre windows in your phone . click yes and restore RootMe restore .

7) After 2-3 reboots your phone is now rooted .

Congratulation ... You have just completed step 2 .:smileyhappy:

[anfer66]

thanks i try 2 step ....!

[anfer66]

finally......!  3 step .....???????? it`s okay post 3, 4,5 steps together ,(but post like your previous steps they are very clear )

[devsatan]

Please post pics of ur phone so that i can verify that are you going in right driection???????????

This is also necessary due to the reason that I could see whether you are doing the things or just keep asking me.

After that I will Post 3rd step for you and after that 4Th and the last step.

It's good to be on Jelly bean.