Yes.. there are some adjustments.... you can move the boat fore or aft slightly to adjust tongue weight (usually by moving the front support) and you can raise or lower bunks to match the hull. Usually, the axle placement is not easily adjustable if at all. By taking 14" out of tongue it limits the amount you can move the front support. In any case.... if you shorten the lever arm, in order to keep your tongue weight the same you need to move the axles (fulcrum) forward. You cannot just shorten a lever arm, not move the fulcrum point and expect it tow safely.
As to liability.... look at the video I posted. An improperly balanced trailer, too light or too heavy in the tongue weight will fishtail as in the video.
So if you start fishtailing and get into an accident.... and some witness says he saw you fishtailing just before the wreck... guess the first place they are going to look? The trailer setup....
As to homemade trailers... yes they exist, however, they are inspected before they are given a VIN to allow them to be registered. I know I have built a couple.
Sorry you guys disagree... best of luck!
Woodsy