Hi Iuri,
excellent news. Did you try "contacts::populate::crm" to get a decent setup for a CRM system ?
Looking forward to see where you are going, though I have to say I don't quite understand what you mean by "fields" and "filters" with regards to contacts.
By the way, help is highly appreciated by the SQL tuning gurus. If anyone knows how to tune queries and has some time to work through a challenge, feel free to post here, contacts has a nice area to let your beard grow very long.