It sounds like you're not using a grid setting that makes sense. For symbols, you generally do everything on a 0.1" grid, and only for some fine details will I switch to a finer grid setting to draw things like the arrow of a bipolar transistor emitter. Even then, how many times do you have to draw that emitter arrow? Once - do it once and copy it. Then, that arrow is exactly the same everywhere and things look better.
For the package, the grid can help out a lot here as well. If you get one pad set to the right dimensions and your part uses for example, multiple pads on a 0.65 mm lead pitch, you can set the grid to 0.65 mm and then duplicate the pad and drag each pad out to the rest of the locations. Grouping objects can also be helpful too.
Finally, there are some things that the editor is very clumsy with, but the libraries are in a text XML format, and you can edit them directly using your preferred text editor. Sometimes I will do this to do a global search and replace to set a feature from one size to another without having to tediously select and enter the new dimensions.
I think most CAD programs are annoying in some way or another, and they're all different somehow, but the Eagle editor is definitely good enough to get things done, and if all else fails, you can edit the XML directly. Best of luck!