If I don't respond to your post, then it looks like I have backed down... which is exactly what you accuse me of doing. Therefore, I am obliged to counter your accusations with the following.
I haven't backtracked one iota. I accepted new information as it was made known to me and reacted accordingly. No one has vision that can discern how well made this trailer is. One would have to look underneath it to see how many cross braces were used, the dimensions of the those braces and the spacing of them.
Unlike you, I don't ASSUME that this trailer meets highway code to the point of being certifiable by the authorities. Instead, I ask questions to try and determine how it has been constructed. No one can determine whether round, square or rectangular tubing has a 1/16" wall thickness or a 3/8" wall thickness just by observing the side of the tubing. The same goes for checker plate or angle. Unless you see the end profile, you are merely ASSUMING.
I know that the tires are inadequate because Jon said so in one of his replies in this thread. Perhaps you should try reading everything first.
As for the deck material, I am not an expert but as someone who has been around to the premises of several trailer manufacturers, I know that not a single one of them would use pine. I have seen 2 x 6 spruce being used but only rarely and mostly as a centre filler between the steel deck area where wheels and tracks are supported. When it has been used for a complete deck surface, then there are cross braces on 12 inch centers to provide the necessary support.
Oak is the preferred species of choice for even small tag-alongs all the way up to 53 foot dry van body trailers. If pine was a good choice, then you would find it in common use.
Very few people can see quality because few people know the difference between junk and quality. And even when they do have an idea about quality, price will often sway them to buy cheap and regret later on when things go wrong.