You're first question is simple, no hot shotter could earn enough to stay in business running 10K trailers; they can't even make a living running under CDL weight. Actually, most barely make a living running legitimate 30+ foot trailers. You'd have to be hauling a pretty valuable load at high rates to run a 10K trailer. That's why guys just starting out are often advised to start with a 26K straight truck, at least they won't even need a CDL.Let me ask something, if it is so easy to circumvent the 26,001lb rule by saying a 26k truck and a 10k trailer is not under CDL....why is it ,that not every hotshot related company in the US has not changed their fleet to match this? If they did not have to jack with DOT, I guarantee they would be all over this "in theary" rule. I am with Case on this one. Now lets get into the 10k trailer part...how do you do that? There are no 5k axles sold.
None of this is "in theary" as you call it, the other poster showed it to you in black and white from the FMCSA. Did you "think" about it? Why would govt regulators even mention 10K trailers in the federal and state law if it didn't mean anything? They put it there for a reason, so that drivers pulling light trailers behind a big truck wouldn't need a Class-A.
As far as 10K trailers there are plenty being sold by all the manufacturers, big and small. Here's a Big Tex, for example: http://bigtextrailers.com/pdf/10eq.pdf
There are many others.