Moving to Bahrain

First of all, please do not create multiple threads for the same topic.  I have deleted your duplicate thread.

1)  Your employer needs to guide you.  But no, originals are generally not required.  See the below sticky for the process itself.

https://www.expat.com/forum/viewtopic.php?id=750635

2) Again, that is covered in the forum and in the sticky.  You have to come first and finish your process before they can be brought over.  It is up to you how to manage this with an employer - some can bring them on visit visa at the same time and then convert it to a dependent visa.  But it is not common practice

3) Not really.  If you are used to GCC employment i.e. housing, visa, medical, flights, schooling....then it is pretty standard to Oman

4) Absolutely no point in transferring a car unless it is brand new and you don't want to lose the value on a sale.  Prices are similar.  It is a hassle to transfer between GCC countries as you do waste a lot of time on bureaucracy and pay fees / taxes

5) It varies from apartment building to building.  Some landlords when renting out for the first time will put in new stuff but in established buildings, you will use existing furniture.  The choice to bring your furniture depends on whether your employer covers shipping and if you have higher quality stuff vs. the place you will stay in

6) It is similar to Oman

7) You can check prices on bahrainpropertyworld or Olx.  Or browse the housing ads on this forum