Ansehelm:

I know little of what's going on at this time, as I've only just started looking at matters of state, but I would like to say this:
I second the proposal by Count Von Hamburg. I must also say that it might be wise to suggest expanding to the east. If we look at the current map of our empire we clearly see that we border 3 enemies (and 4 if you also count the rebels). While other duchies sometimes only border 1 enemy (neglecting the crusades this is).
Spoiler Alert, click show to read: 

By taken atleast one of the Polish cities we will secure our eastern flank as well take loads of resources from them.

This ofcourse can only be done if we have also an army in the west. I think that this doesn't have to be a big army, a small "reaction" force will do.