There is a forum for FM Go in the tabs at the top of this page.
In the inspector, there's a Position tab that shows the size and location of any selected layout object, which can include the height of a layout part if you click its label. These boxes can display data in inches, centimeters or pixels. To change the units just keep clicking the units to the right of one of these boxes until you see the units you want. You can change a selected objects size or position by editing the numbers in these boxes.
There are also alignment tools in this same tab, you can nudge objects around one pixel at a time by selecting them and then pressing an arrow key, there's a T-Square tool available in the view menu...