Is it possible to add a new civic and then make the boxes bigger to accomodate it? If so, how is it done?

If I understood right you want to mod the civics screen.
In the assets/python/screens folder there is a file called CvCivicsScreen that file defines the size of civic boxes. The needed lines are about 32-43 and it looks like this: self.HEADINGS_WIDTH = 199
self.HEADINGS_TOP = 70
self.HEADINGS_SPACING = 5
self.HEADINGS_BOTTOM = 280
self.HELP_TOP = 350
self.HELP_BOTTOM = 610
self.TEXT_MARGIN = 15
self.BUTTON_SIZE = 24
self.BIG_BUTTON_SIZE = 64
self.BOTTOM_LINE_TOP = 630
self.BOTTOM_LINE_WIDTH = 1014
self.BOTTOM_LINE_HEIGHT = 60
Try changing the numbers and see what it affects.

Or you could rip one from some mod. RoM in particular has a massive screen, but the new RevDCM has some newer one that scolls and stuff (I think it's from WoC.)

Right now i have three civics screen to choose from from my mod, Next War Advanced, i am also working on even a better one IF i can get help from the great python personnel.

If I understood right you want to mod the civics screen.
In the assets/python/screens folder there is a file called CvCivicsScreen that file defines the size of civic boxes. The needed lines are about 32-43 and it looks like this:
self.TEXT_MARGIN = 15

Try changing the numbers and see what it affects.

Set this to 14, and a new row will fit into the screen.