If the addon itself broke in a drastic way due to adding that line, my suspicion is that the table syntax was broken in the process. If you're adding a line to a table, make sure that the previous line ends with a comma. E.g.
Code:
[WeakAuras.PowerAurasPath.."Aura145"] = "Taijitu Top",
[WeakAuras.PowerAurasPath.."Aura146"] = "Triangle"
and not
Code:
[WeakAuras.PowerAurasPath.."Aura145"] = "Taijitu Top"
[WeakAuras.PowerAurasPath.."Aura146"] = "Triangle"
Note that I'm not sure if this is the correct way to add textures to WeakAuras or if other things must also be done, etc. I've never edited the addon myself. But based on your description of things severely breaking, I'd guess this is why that part happened.
As for the rest, I'm not really qualified to answer since I've never done this myself.