There are several Mouse Configurations 3. The zoom centering feature is selected as default and enables you to zoom into the area to which your mouse cursor is pointing. De-activating the feature will zoom in and out of the center of the screen. The zoom speed can be changed by adjusting the wheel sensitivity. The higher the number, the faster the zoom. Moreover you can choose which modifier key (among CTRL, ALT and SHIFT) should be used to select several parts and duplicate them in combination with the left mouse button.
When you Copy/Paste 4 some parts on your map, you can decide to add an offset in order to distinguish the copied parts from the original ones (otherwise they will be pasted at the exact same position). However when you want to move some parts from a layer to another one, usually, you don't want them to be off-setted. So the combobox let you choose when the offset should be added: either never if you don't like the offset feature at all, always, or only if you paste on the same layer.
At the top of the Rulers frame 5, you can configure the ruler attach point size in pixel. Be aware that if you choose a too small value, you will have difficulties to grab the attach points or click on them. Just under there is a checkbox to let you choose if you want BlueBrick to switch to the ruler edition tool after each Ruler creation, which is the default behavior. However, if you prefer to change your Ruler tool manually, or if you plan to create a big series of Ruler in a row, you can uncheck that option.
In this preference page, you can also configure the default ruler appearance 5 i.e. the appearance of each new ruler created. However, note that this is not the easiest way to do it. A much easier way is to right click on a ruler that you like in your map, and choose the menu Use as Template in the contextual menu. It will automatically set almost all the settings of this "Ruler" frame. Read the Using Rulers section for a complete description of those settings (except for the first two ones, please read above).