We currently don't provide much in the way of customization on the HP ThinPro clients (see bug 5186 for more UI). These devices are also fairly locked down, so there isn't any clear options for administrators to modify the startup of the ThinLinc client to adjust things.
One such modification that has been requested is the lockdown features of the client (--lock and friends).
We currently allow modification of the username, password and server address via the HP ThinPro registry (see bug 7213 though). Something similar could possibly be provided for the lockdown features.