Thanks for the chance to help. I am an attorney with over 12 years military law
I spent a year in "purgatory"...my job was to review FOIA requests and release information under the FOIA. I know the FOIA. Let me tell you, its complex...much more so than many other areas of the law.
When I say complex, I mean the law that relates to specific examples...what is and what is not releaseable...that is complex. Each year the government puts out a new book with the latest law in this area...the book is several inches think.
The concept is not complex...all government information that protected by the privacy act and is not classified is releaseable under the FOIA UNLESS it falls under one of the 9 exemptions. You can see the 9 exemptions here
SO in theory its very easy...and most stuff should be released.
In practice? Not so much. Since most documents...at least the documents you want, fall under either the Privacy Act or one of the nine exemptions.
Lets address your questions in order
Can I get my records from the IG for the three cases I brought before them?
Perhaps...perhaps part of your records. The exemption that may apply to at least part of the records is b5.
(b)(5) EXEMPTION - Privileged Interagency or Intra-Agency Memoranda or Letters<
This exemption protects "inter-agency or intra-agency memorandums of letters which would not be available by law to a party ...in litigation with the agency." As such, it has been construed to "exempt those documents, and only those documents, normally privileged in the civil discovery context."
So in the file, I suspect a portion of the file will be protected under this exemption.
Can I get retention board minutes?
This I would argue that no exemption applies...since the Privacy Act will not apply to you for your request.
Can I get email correspondence that references my between HQ departments?
No. No way. This is clearly a b5 exemption.
So you can get at least part of what you want...but I suspect not everything