Hi,
1. There is no option for that.
2. Yes, that's possible.
3. With HikaMarket Multivendor, you can have suppliers as vendors and the system will generate a sub order of the products of each vendor so that each one can know what to ship for example, or can managehis orders, etc.
4. There is no automated thing like that. You can export your orders as CSV and then import the CSV to third party tools.
5. Demo website is working fine for me. Note that it is reset every few hours and when that happens, there is a few minutes of down time.