How do I add more Status types to work items?

There are a few of steps you'd need to take to accomplish this:

1. Add the new status choice to the sg_ztemplate__wit.json file in ../modules/scrum/zing (or a copy of that file)

Look for the "status" section; the list of possible choices is under the "allowed" property.

You might add:

"allowed" :
    [
        "open",
        "fixed",
        "verified",
        "wontfix",
        "invalid",
        // need a new comma here
        "duplicate",    
        // no comma here
        "needsqa"       
    ],

to indicate a waiting-for-QA status.

2. Tell your work item database to use this new template.

The steps here are:

1. Read the file
2. Parse it into an object
3. Open the repository
4. Open the database.
5. Begin a transaction
6. Set the template
7. Commit
8. Close the repo

In code, that's along these lines (error checking and exception handling removed for brevity):

var wit = sg.file.read("sg_ztemplate__wit_newstatus.json"); 
var t;
var repoName = "testrepo";

eval('t = ' + wit);

var repo = sg.open_repo(repoName);

var db = new zingdb(repo, sg.dagnum.WORK_ITEMS);
var ztx = db.begin_tx();
ztx.set_template(t);
ztx.commit();
repo.close();

That's the easy part, since the new template will follow that repo around wherever it's cloned, pushed or pulled.

But if you want to see that new status in your workitem edit/display page, you need to:

3. Edit .../ui/workitem.js

And maintain (or redo) those edits across instances and upgrades.

Look for the collection of status.addOption(...) lines, and append one with your new status(es) and the appropriate description(s):

status.addOption("open", "Open");
status.addOption("fixed", "Fixed");
status.addOption("verified", "Verified");
status.addOption("wontfix", "Won't Fix");
status.addOption("invalid", "Invalid");
status.addOption("duplicate", "Duplicate");
status.addOption("needsqa", "QA Needed");   // the new guy