Only if you've saved your SHSH. If you don't know what that is then no sorry.
You cannot bypass the "Firmware" password, you HAVE to erase and reinstall the OS if you forgot the "Firmware" password.
No. Linux cannot overwrite iPhone's firmware, as it is encrypted. Only iTunes can do that.
No
Reinstall them or check if they are compatible with your firmware.
Us Jailbreak me on the iPhone 4 if you have the firmware 4.0
To check the bootrom on your iPhone: Settings General About At the Bottom - Modem Firmware
Update the software in iTunes and it will do it for you.
Allow it
this is problem seems to be with firmware.You have to reset or reinstall the firmware to recover the security code. I believe you can reinstall it ...
Update to the Latest Firmware.
You should be able to download it from http://warez.selvestr.com/?apple/firmware/iphone/ One version is not compatible with iTunes so read carefully.
yes to the latest firmware upto date