>Does anyone has some opinions about if this is a viable option for
> > design?

Sure. Customers should go in a Customers table. Vendors should go
in a Vendors table. Employees should go in an Employees table.

Don't put everything into a single table.

Sure, a customer and employee both have an address - make an
Address table, or an Customer_Address table or whatever.

Or make a Contacts table with a ContactID, make a Vendor
table with a foreign key to Contacts and put a row in table Vendors
if a contact is a vendor. This way, you can also create a Customers
table and put a row in there if the contact is both a vendor and a
customer.

With regards,

Martijn Tonies
Database Workbench - developer tool for InterBase, Firebird, MySQL & MS SQL
Server
Upscene Productions
http://www.upscene.com