What posts in particular?

Were they discussion posts? Listings? Blog posts? And why do you think they were removed?

If you posted a lengthy message to a tribe I was moderating and didn't stick around to discuss your position with the tribe and on top of that were not a regularly participating and contributing member of that community I would strongly consider removing your post.

You obviously care a great deal about the message you have to communicate and take a lot of time and effort to deliver it to people and I think this is quite admirable but I believe you would do well to become familiar with commonly accepted web etiquette.

I just searched for your posts, and you have 346 active posts in various tribes. I didn't look for listings or other types of content.

I can't speak to why an individual post might have been removed from a tribe, but moderators have the right to remove anything they want from a tribe they moderate-- listings, discussion posts, photos, events, even members. If a moderator removed something of yours, take it up with them individually.

Listings do expire after 30 days. They are intended to be temporal in nature, e.g. announcements, things for sale.