Question: At what certain amount of deleted post will cause a permaban? I lost count because I delete all this notification on my message because it's already annoying at that time.
Only the officials from the forum like Global moderators or admins can give you a specific answer to the question but from my experience and observation since all these years I may say that there are no actual number to it. The forum also does not have any point system too to ban you automatically. The mods manually ban a user. In that case, it entirely depends on the judgement of the mod who is banning you.
According to your information, since there is no automatic system behind the post deletion, the moderators delete the posts manually, so my question is if someone reports against someone or a post, does the moderator not monitor the post and delete the post only based on the information of others? Do you? If moderators delete posts based on other people's reports without checking posts, it will be very harmful for every member.