Is there a provision for Displaying Username in the title bar next to Date and time in Milestone XProtect Smart Client and Can we create login authorization for whenever customer wants to start/stop Manually recording a certain Camera's feed.

MIP
,
2

To my knowledge, first is no, the second is also no. But there might be a workaround for the first one by implementing your own toolbar button in MIP. Please see this sample, it might be helpful for you. As you can see there are customized text on the top of the view. You can put username instead of the color name.

https://doc.developer.milestonesys.com/html/index.html?base=samples/pluginsamples/sctoolbarplugin/readme.html&tree=tree_1.html