I'm going to go right ahead and take Stinky's side with this one. I'm going to school to get my B.S. in Welding and Fabrication Engineering Technology and out in the field weld prep is HUGE. Why do you think in most industries every welder has his own fitter and prepper?
Like Stinky, i'm in the shop 4 hours a day, and have classroom theory for 2 hours. The single most important part of a weld joint is prep. If the joint isn't prepped perfect, you're weld will fail if it is exposed to it's rated loads. You guys are saying hands on experience is better than some degree. Well guess what, I have both. This school is one of the tops in the country simply because they give so much hands on and out of position welding that you are almost completely prepared for anything you could encounter in the industry. Sure, sometimes it is impossible to prep a material that is to be welded completely. In the shop, we practice ways to get around prep work, or alternate ways of prepping materials such as different solvents and acids.
If you think those welds are good, so be it. I'm telling you right now though, just a visual inspection of that crossmember shows me you don't know what you are talking about. Sure, more wire speed gives you more amperage for better penetration, but if your wire is bouncing off the base metal, then your voltage isn't close to high enough to support that amperage setting.
It probably sounds like i'm trying to be a know it all here, but i'm just trying to look out for your nephew's safety.