In-Game Modifications?

[BlueAlchemy]

if you click and hold the bottom right corner of certain inventory's you can shrink them to 2 row's minimum, you can't do that for homunculus though, but you can use ctrl + r to jump in and out of the homunculus window.

EDIT: another thing you can try is increase your games screen resolution, I did that once and it shrank the guild window quite a bit.