If you have mobile data always on then it will follow the sync schedule you have set up, hourly, every few hours or manual refresh/sync when you open an app or widget. However with mobile data turned off, unless you are on wifi, there will be no syncing or anything as far as data use is concerned because there won't be a data connection
Also on a side note to save space on my screen for the common apps I use, I use an app called dock4droid. It's a little tab that you can place somewhere along the edge of your screen tap it to show most recent or most used apps. Also convenient for switching to and from apps without going back to the homescreen/app drawer