Do I use AutoFixture correctly?

I'm working on a project where I have some recursive data structure and I want to generate a fixture for it.

I've been using AutoFixture for many years but never got the time to ask this simple question, do I actually use it correctly?

So here is the code I'm using for the fixture:

public class XmlCommandElementFixture : ICustomization
{
    private static readonly Fixture _fixture = new Fixture();

    private XmlCommandElement _xmlCommandElement;

    public int MaxCommandsPerDepth { get; set; }

    public int MaxDepth { get; set; }

    public int MaxPropertiesPerCommand { get; set; }

    public XmlCommandElementFixture BuildCommandTree()
    {
        _xmlCommandElement = new XmlCommandElement();

        var tree = new Stack<XmlCommandElementNode>();

        tree.Push(new XmlCommandElementNode(0, _xmlCommandElement));

        while (tree.Count > 0) {
            var node = tree.Pop();
            node.Command.Key = CreateRandomString();
            node.Command.Properties = CreateProperties();

            if (MaxDepth > node.Depth) {
                var commands = new List<XmlCommandElement>();

                for (var i = 0; i < MaxCommandsPerDepth; i++) {
                    var command = new XmlCommandElement();
                    tree.Push(new XmlCommandElementNode(node.Depth + 1, command));
                    commands.Add(command);
                }

                node.Command.Commands = commands.ToArray();
            }
        }

        return this;
    }

    public void Customize(IFixture fixture)
    {
        fixture.Customize<XmlCommandElement>(c => c.FromFactory(() => _xmlCommandElement)
                                                   .OmitAutoProperties());
    }

    private static string CreateRandomString()
    {
        return _fixture.Create<Generator<string>>().First();
    }

    private XmlCommandPropertyElement[] CreateProperties()
    {
        var properties = new List<XmlCommandPropertyElement>();

        for (var i = 0; i < MaxPropertiesPerCommand; i++) {
            properties.Add(new XmlCommandPropertyElement {
                Key = CreateRandomString(),
                Value = CreateRandomString()
            });
        }

        return properties.ToArray();
    }

    private struct XmlCommandElementNode
    {
        public XmlCommandElementNode(int depth, XmlCommandElement xmlCommandElement)
        {
            Depth = depth;

            Command = xmlCommandElement;
        }

        public XmlCommandElement Command { get; }

        public int Depth { get; }
    }
}

And this is how I'm using it:

xmlCommandElement = new Fixture().Customize(new XmlCommandElementFixture {
    MaxDepth = 2,
    MaxCommandsPerDepth = 3,
    MaxPropertiesPerCommand = 4
}.BuildCommandTree()).Create<XmlCommandElement>();

I have few questions.

1. Is there a better way to do it?
2. Sometimes fixtures gets large and it kinda bothers me that I don't test it! do I need to test it?