Quick Question regarding number of instances...

I am developing an application for a client who already has a liscensed SQL server running. They have a software package that requires an instance using "Windows Only" for the authentication mode. I need an instance to use "SQL Server and Windows" for my application to be able to speak with the server from other computers on their network (or at least I believe I do...).

My question is, "is there any restrictions on the 'number' of instances an institution can run on a computer that is liscensed to run the software"?

Alternately, if there is a limit, I need to figure out if it is possible to set up the application (VB6, btw) to connect to the server from outside the host computer if it is using "Windows Only" Authentication. The application will be installed on several computers in the client's network and I'm not familiar with how to dynamicly poll the 'current Windows Login' information.

It would be much simpler for the application to create a new instance with the desired authentication method, but is there a security issue in doing this? Would the data be any more at risk to outside corruption using the SQL server authentication mode?Number of named instances if default instance is already present is 15. Total number of instances including default instance cannot exceed 16.

Windows authentication is safer simply because there is no need to provide user ID and password in clear text. If you use OLE DB Provider then "Intgrated Security=SSPI'and for DSN-less connections, - "Trusted_Connection=Yes"

queueing and submitting reports

i am just wondering if anybody knows of any third party software, or a
good way to implement the following using the webservice.
in our current reporting engine (inhouse designed)
users can select a report, select the parameters and submit it to be
run, when its complete it shows up in a sort of inbox, and then can
select one or more and click PRINT ..
i'm wanting to implement the same sort of workflow in reporting
services because reportmanager just doesn't have good workflow for such
circumstances.
any ideas, hints, systems out there that already do this would be
appreciated. whether rs 2000 or rs 2005
in implementing it manually i see a problem with the fact that the
'prequery' i.e getting parameters from lookups is done at the same time
that the reprot is run.. is there a way to intercept just the parameter
gathering GUI and gather the parameters from that (so that we can make
our own queueing and rendering via the webservice engine?)
Karlno ideas anybody?