showing vendor-data after customer-login

-- HikaShop version -- : 2.5.0
-- HikaMarket version -- : 1.6.5
-- Joomla version -- : 3.4.3
-- PHP version -- : 5.4.27
-- Browser(s) name and version -- : Firefox 40.0.3

My Multivendor-shop has the following constellation:
All products are edited only by the shopowner not by the vendors.
All Vendors all selling the same Products (same price, same variants).
Product-duplication is not allowed because of generating huge amount of products.
And a Product should not be assigned to a spezific vendor.

1.) Is it then still possible that a Customer is assigned to the nearest vendor in relation to customer city or zip code during checkout?
is this done with "Allow zone vendors" in the configuration?
how should i configure the "category options" in the section "market options"
"Parent category for vendors": none or the product category ?

or if the above solution does not work:
2.) Is it possible to store a prefered vendor for a customer and to show the Vendor-name, Adress, E-Mail, Tel...
automaticaly in a modul after the customer logs in.
The Customer should select his prefered Vendor at Registration (changeable later in his profile)
I can define a custom field "prefered vendor" (type: Vendor selection) in the user-table but how can i display the vendor-adress... automatically after login
3.) the "prefered vendor" shold be automatically preselected for the customer during checkout-prozess for future purchases!

how much will it cost to realize Point 2 and Point 3
(if www.obsidev.com will do this)

regards