Christina it is not complicated it is just a workflow that you do to take pans. I level for the middle shot, sweep left to see it the virtual horizon tool moves if not then sweep right to check if ok than shoot. It is almost impossible to get everything 100% level so do not worry about it, remember with the shots you did you got a whole lot of sky and foreground so you can crop it needed.
Now Christina I am adding a link to this thread of something I use, now you do not need this for what you do, myself I use it a lot as a shoot a lot of pans of landscaper and such, but no birds (which you excel at, Oh and bears too), this tool lets me adjust and level the tripod base very quickly with out having to adjust legs. It is not for everyone and not you at this time, maybe in the future who knows.
http://www.feisolcanada.com/?products=lb-7572
Cheers: Allan