It would be nice if [right click on a user] -> Modes -> Give Op would try to set op with the help of the ChanSevr (or a other user?) by sending "/msg ChanSevr op [currentChannel] [nick]" if the default method (you are no op) won't work. Reproducible: Didn't try
The ChanServ user could be set in the server list, so each sever can have it's own ChanServ user (name).
There is too much variance between network services implementations to offer such actions by default, since we can't support them reliably. We recommend users use the Quick Buttons system to set up their own custom actions. Starting with the recently released 1.5rc1, Quick Buttons that operate on users can also be shown in nickname context menus, so you can add your own "Op via ChanServ" action to the context menu this way - not a lot more work than setting the name of ChanServ somewhere, and since this wouldn't be enough depending on the network (you might also have to set a custom command anyway), it comes out to be more or less the same amount of work, but is more flexible from an UI point of view.