Simple root question topic

Hi everybody,

I want root HTC One and have some question.
I found thread to root, but I have some questions:
(Phone is HTC One Orange UK sim free)

1. My hboot is 1.54.0000
I need to downgrade hboot to 1.44 or not?

2. HTC One is not on the list http://www.htcdev.com/bootloader/ supported devices.
What I need to select?

3. After unlocking, is my defaut fabric ROM will working?

4. How to restart htc one is hold and freeze?
I removed battery on HTC Desire but on HTC One I cannot do that!

Thanks