Another concern regarding deleting that Albert has raised is that even if
you have approvals configured on the document  library deletions do not have
to be approved - a document is simply deleted without anyone even knowing.
With alerts configured however you can track that a document has been
deleted, however the user name is displayed as unknown so you don't even
know who deleted the document.

If there is anyone that has a way to set  permissions without the delete
right it would be greatly appreciated.

This may not be what you want but here are some ideas....



Turn versioning control on - at least if someone does delete  a document
you have prior versions.

Set permissions to read only for people who are not collaborating.

Publish the document  to the Portal so users can access the document as a
read only file and only have a few

People (who are collaborating on the document) have editing rights in
the document library  on a site.