I would not worry about the metal spur; as long as your mesh is right you shouldn't have an issue with the plastic one.
I have broken 2 of the plastic steering bellcranks where the servo link attaches to it. I was also popping the stock ballcups off so I swapped the ballcups and ballstuds to the Losi ones. No issues since. I thought about captured style like on the Slash, but with the speeds associated with this truck, I wanted a weak link somewhere.
As for the wheel nuts, I bought the HPI serrated nuts (non-nyloc) and they flat out don't move. I think they were $4-5 for a set of four, pricey but worth every penny.
I love mine, but it's parked for a while until I buy new electronics for it. Planning a Novak Havoc Pro with an HV 5.5 or 6.5, but I've heard some talk about a new Ballistic HV series and it may be worth the wait.