Hi,
1/ You can access to the orders in the HikaShop backend.
In the front-end, the vendors does not have more right on the orders ; but the administrator (main vendor) can have same rights and same features than in the HikaShop backend.
It is not possible to re-assign a sub order to another vendor like that. But it is possible to add/remove products in an order (the main order) in order to remove a "vendor a" product and put a product from the "vendor b".
2/ Vendors can't create orders in the front-end.
I already talk about it few times in the forum ; that's not a good idea of HikaMarket because it would create some kind of "security breach" where vendor could create fake orders in order to receive money from your store without any real transaction.
Regards,
Jerome - Obsidev.com
HikaMarket & HikaSerial developer / HikaShop core dev team.
Also helping the HikaShop support team when having some time or couldn't sleep.
By the way, do not send me private message, use the "contact us" form instead.