Hi.
You do not need to disable UAC. UAC will only deny you the option of remotly deploying using Symantec Deploymnet Wizard (this is not something you will use on 14K computers).
Note that UAC will also disable users from opening the SMC gui.
I have deployed with UAC many times and the only thing you must make sure is that you install with elevated rights.
Regarding the Download Insight option:
You migh get the Download Insight Option error if you have disabled Download insight by policy and not checked the LOCK key next to Download Insight
Torb
.