Sorry, but i dont understand ur first question

.
I didnt try to install another rom yet. But i will install a new one tomorrow or thursday. I am not home now.
i mean if you're phone bootloader just had unlocked but still
S-ON..so you must flashing boot.img too that are extracted from the rom.zip that you already installed..
you pc must already had ADB / SDK...if not..you can download from
here.. or minimal adb and fastboot from
here..
1. extract the rom.zip that you already installing...and copied boot.img from there to adb / sdk folder on your pc
2. turn on your phone with pressing and hold volume down + power button until inside bootloader...then select
FASTBOOT mode..
3. connect your phone to pc via usb...then open cmd and change source to your adb / sdk that fastboot.exe placed folder..then type "
fastboot devices" enter (to check first that your phone already connected) if success connected that will be prompt your phone serial number
4. then continued typing "
fastboot flash boot boot.img" enter
5. after finish..typing "
fastbot reboot" enter
6. done..
all command type without quote
hope this can help..