Oh my god, I'm so biased to dutiful auditions. Bonus points for filling out the info.

You do sound a little stiff. You're getting great emotion and play with your takes, but I'm getting the impression that you might be trying to hold back that accent I'm getting hints of? I can't say for other casting directors, but for me, don't be afraid to use it. Right now, trying to stifle it is adding a tension and uncertainty to your lines that we don't want. Joe, or any character really, should feel open and bubbly. That tension in your voice is taking away from all of this wonderful character you're building in your lines. If you have to be British to give me a fun and bubbly Joe, then be British! I'd much rather have a more interesting and diverse voice cast than a full American sound from actors not shining at their full potential.