What is separated when I use multi-company setup?

Docs are not clear on this. Is there a list of things that are separate when I use multi-company setup?

Let’s say I have 2 brothers. We are doing the same business, ie. we are the same brand, in different areas under different companies. Reasons I see for going multi-company route is:

F1. We have the same products
F2. We want to see each other’s stock
F3. We want to see each other’s customers because they might move to our area
F4. We want to share each others supplier contacts

What I am not sure about and think are reasons against:
A1. Not sure if we can separate the stock
A2. Not sure if we can separate the price rate
A3. If someone in other company makes mistake and deletes item we all lose access to it?

This will work fine.

Warehouses are separated by company so the stock will be separated as well.

Price List doesn’t seem to be company specific, so prices will be shared. You can use different price lists for each company, if you wish.

Yes, shared data can be modified by both companies and will affect both. But, for example, you could prohibit deleting items for everyone except the system manager.

Thanks, this clears it up. Thanks a lot.