Idk why there is a 6 post limit in the first place
that's not how you fight spam, lemmy needs users and We should not "scare" them. Limiting threads just de-incentivize people to remain here
Also if you're at University you share the same IP with many people, I know that lemmy isn't that popular but isn't the good mindset for fighting spam
Probably because there are not many users so there isn't the need for many different rules or specific ones