State Patrol Truck enforcement here looks at the combined capacity of the trailer and towing vehicle to determine if a CDL is required of the driver, has nothing to do with the actual load carried; that comes in play when you have a CDL and forced to go through a weigh station. Dual axles are required to have brakes on both. Around here trucks with obvious farm equipment or smaller tractors are largely ignored unless there is something visibility wrong or unsafe. The proverbial tail wagging the dog or uncovered loose cargo will get you pulled over every time observed. A trailer larger than a utility type W/O a manufacturer's load rating tag can get you a ticket, if stopped for inspection. Some manufacturer's under rate their 12-14K trailers to accommodate us non-CDL drivers with less than 12K ratings.
I have a 16' tilt bed trailer with a 4' bobtail; works great for my BX W/FEL and BH plus several other implements. Sometimes I have stuff on the bobtail. Axle placement is critical to planning loads to assure proper tongue weight so pays to have some longitudinal flexibility. For mine; tractor over the axles is perfect. I have pre-planned various implement loads around the tractor so I can place those on with the tractor prior to loading the tractor; even can use the BH to lift loads onto the bobtail. Sometimes I load w/the BH swung to one side to get another implement on. My 50 GL fuel tank always sets on the front corner. Installed extra tie down points for all the options.
With your setup length is your concern not capacity, you will never reach 10K #s.
Happy trailer hunting, Ron