Just to preface this, I am NOT an expert or professional in any sense of the word, so my opinion is probably not quite as valid as other much more intelligent people who frequent this forum, but I figured I'd put my two cents in anyway since that's what the internet is here for
I saw somebody the other day with a lowered civic with no camber kit, their tires were facing out diagonally at like a 45 degree angle, and it made me wonder how much money they burn through on new tires every month
So yeah, clearly it can be done, but I wouldn't do it
Also if you try to sell it lowered without a kit it might be a little trickier than if you had either left it alone or used the camber kit, I passed up a couple otherwise fair looking civics (fair looking just based on pictures and sellers description, I didn't even bother to check any of them out in person) because the seller lowered them without the kit and it just made me wonder what other things they half-assed on it
Good luck with your endeavor!
<3