The changes you're trying to make should be quite simple, you definitely should be able to change the time to 1 - I'd recommend altering the files directly (with notepad or similar simple text editor) instead of using a program like Hadrian, especially as you're changing a mod that it probably wasn't set up for.

to change the construction time that way you just need to open export_descr_buildings.txt, find the right building and change the number after 'construction'
}
construction 6
cost 6400
there's an EDB guide here
https://forums.totalwar.org/vb/showthread.php?t=50439

and EDU guide here
https://forums.totalwar.org/vb/showthread.php?t=88859