Customizing Entityreference

We have a drupal 7 projekt. On a content type "project" where a domain must be chosen that must be a valid root domain. Host and domains are in a separate entity calles "domains_hosts". We use an entityreference autocomplete field to search on existing entity (entity domains_hosts). New entry's like "[login to view URL]" can be added, we use the module entityreference_autocreate for this. It works but it is not really stable. What we need is... Validation 1. Validation of the User Input before the node is saved. Input must be valid domain like "[login to view URL]" oder "[login to view URL]". 2. If a user enters something crazy that is not a valid domain "meindomain"then throw an error. 3. If a user enters a full URL like "[login to view URL]" the the domain should automatically detected, in this example "[login to view URL]" and searched in the entity or added as new entry. Alter the Autocomplete Query The entity "domains_hosts" has entry's of hosts ([login to view URL] ) and root-domains ([login to view URL]). the query must only return root domains. Root Domains are marked in the entity with a boolean "1" (is_root). On Save If Validation above is done and the user has choosen or domain is new, add the project node-id to the choosen root domain entry. Marking in root domains that already has project node. (related to above "alter the autocomplete query") A root-domain and projekt have 1:1 relationship, so each root-domain can have only one projekt. If a user makes a query on the entityreference field and a projec node alredy exists for it the we mark it in the autocomplete suggestion as disabled and a little note "already attached to a project". A Drupal Coder with expierence on entityreference can finishe this project fast. We provide access to the dupal projekt via FTP and Admin acces. Devel is available.