Usually users don't expect software immediately, a reasonable SLA is 24 hours, typically it normally gets delivered within 15 mins AD replication plus 60 mins max AD update interval plus max 30 mins filter update interval plus max 60 mins agent update interval=less than 3 hours.
You shouldn't need to diagnose if the install went OK or not, they should almost always work if well tested. The admin will run Software Execution reports and look for repeated failures, I recommend using a policy that runs once immediately and repeats every 24 hours, so even if the first install fails for a one off reason it will install 24 hours later.
Have you considered the Software Portal for user requests?
I can't think of an easy answer, I'm afraid. You need to present this as a management problem, not an Altiris problem. Your management want to allow tech to install to any PC but not all PCs.