You can get information only about character you are currently logged on. It is not possible to query information about offline characters even if they are on the same account.
And for the character name. I don't recommend using GetUniqueNameForCharacter(charecterName). This function will make difficult displaying character name somewhere. This function merely joins character name with server name and thats all (<server>-<character>, "NA Megaserver-Vertol"). As character names are always unique, you don't need it. Use GetUnitName("player") or better GetRawUnitName("player").
As for the saved variables, check comments here:
http://esodata.uesp.net/100010/src/l...dvars.lua.html
Of course, it isn't necessary to use default ZO_SavedVars object if you don't like it. You can use saved variables table directly and create your own data structure. Just do not forget, your saved variables table won't be accessible before EVENT_ADD_ON_LOADED is fired, so you should initialize them in handler for this event.