Just wondering about your expertise and what it means to this trailer.
Anyone who would consider tackling a project of this magnatude must know what they are doing, and be proficent at it, or will find out the hard way that they made a major mistake. Considering using a skill saw with an abrasive blade to make these cuts is probably not something you want to try. You will wear out many, many blades, trying to do a job that should require a torch setup, or in todays advanced world, a plasma cutter. ( I prefer the torch)
I built a 27' trailer for a customer, to his spec's. He spec'd it out wrong. After completing the trailer, he asked me to modify it, which is when I started asking serious questions, and he started backpeddling due to the money and expense of the the required modifications.
I finally relented and added six foot to the rear of the trailer, knowing it would not handle right, and had him come over with his truck and pull it empty for a short drive. Unfortunately, it handled fine, so we went back and loaded up a reasonable load compared to what he wanted to haul. Made it almost half a mile before the darn thing started swaying, and he panicked, hitting the brakes. We stopped just shy of connecting trailer to truck in a jacknife situation. He never questioned my judgement again, and I always asked way too many questions to figure out just what he was trying to do in future arrangements.
You situation is the reverse of what he did. You are removing lenght from the rear section of the trailer, behind the axles. This should improve the handling caracteristics' of the trailer, but will add considerable more weight to the tongue, due to not being able to center the weight on the axles. It also will not help in the manuevering of the trailer, since the wheelbase will not be changed, which is what you probably are after. Removal of the front axle is also not going to help that. Removal of the rear axle will shorten your wheelbase, but will decrease the capacity of the trailer.
What you are doing basically is making an arrangement similar to a boat trailer, with the axles nearer the rear of the trailer. Nothing wroing with that, but there is a reason trailers are built the way they are. Most of the weight in a boat is on the rear of the boat,which centers it on the rearward placed axles. Most items hauled on a flatbed trailer aren't like that,in fact most are quite the opposite.
Bottom line, yes this conversion is possible, but unless I miss my guess, your going to need some serious help with it. Running welds vertical and overhead that will be under extreme stress aren't for the average homeowner with a mig gun, and cutting the trailer with a skill saw will soon tell you that your in over your head.
I hope I have added some information to you post without insulting your intelligence. If you are qualified to handle this type of a modification, then you probably already know the answer to your original question.
Respectfully,
David from jax