You’d be surprised at just how big a tyre you can fit on the TCX.. I’m using 38C Gravel Grinders for the winter when not racing (then I’m using Limus,Grifo,baby Limus,Almanzos), and I’ve a set of 38C Barlow Pass for uber smooth long distance hacks on the road (NCN hacks).
Guards do fit, look plenty ugly with them on IMO, if you intend to do Winter on it. I’m not a fan myself, it’s a CXer so you should expect to get muddy..or grimy.
I’ll agree on the decals and graphics, sadly Giant seem to imply Bold statements rule..
I have some 42′ bars and a 100mm OD stem if you need to change your position (assuming thats not already on it)