I might be easier to implement the denyInsert and denyUpdate checks as a custom validator, in the same function that is validating `unique`. This would (a) put the check in all the right places automatically and (b) allow you to return an error type, which could be used to display errors and (c) prevent having to loop through and parse keys, which simple-schema already does. I'm not sure if anyone would care about having an error for this, but because of (c), I think it's easier.

Something like this:

```js
self._simpleSchema.validator(function(key, val, def, operator) {
    if (def.denyInsert && !operator) {
        return "insertNotAllowed";
    }
    if (def.denyUpdate && operator) {
        return "updateNotAllowed";
    }
    if (def.unique) {
        var test = {};
        test[key] = val;
        return self._collection.findOne(test) ? "notUnique" : true;
    }
});
```

The `operator` argument is not currently passed, but it could be easily. This would require the changes in the devel branch, but I'm planning to merge those into master and release before I merge this PR anyway.