1970 tiderider 19ft.. weight issue

[phil2besure]

2 issues with the weight of this boat....its an i/o small 4cycle motor....right now its sitting on a 22ft single axel trailer....should i consider putting this on a duel axel?? i put new heavy ply tires on but the still get that flat look...im pulling it with a durango and it doesnt have trailer brakes and it makes me kinda nervous bc this tri hull is heavy to tow....2nd its an enclosed bow has 2 seats and a railing infront of the passenger seat...plate says 9 people or 2500 lbs...is it legal to have someone standing and holding the rail like a center consel since its an enclosed bow?? or do i have to have mounted seats...im not new to being on the water just new to be a boat owner. and want everyone safe when underway. cause i know the coast guard is out there doing checks all the time bc i got stopped alot on my pwc. can anyone tell me alittle about these type of boats...i put alot of time and money to get this boat purring and it seems like this model is very hard to come by..i have all service records all the way back and the actual sticker for the boat somewhere. thanks for looking Phil....also i have posted a question about the engine on this boat in another thread if u can help