You can include user/password in your connection strin in the QVW script itself. Then, it won't ask it every time you reload.
As matter of fact, you can have this whole string stored in an XML file, and load it in every QVW. This way your string is secured as well, and if you change your app server ip or name, just change here in the XML and all your QVW are running again -> No change needed in 100s of QVW files. :-)
To find the complete string, open a new QVW, connect to SAP from custom data source, enter system, client user and password. When you press ok, it will paste the complete connection string. Just copy this in every QVW or in a common XML/QVS file. The password you will get will be encrypted --> no security issues.
Hope this helps.