I do not recommend 4000 pounds dry with 4500 pound tow rating. Closer to 3500 pounds, or 3200.
Check your owners manual for front area limits with respect to the 4500 pound tow rating. Most that I know of with limits under 5000 pounds also have front area rating that exclude full high travel trailers. A 4500 pound loaded TT will have about 550-600 pounds of tongue weight, so also check the receiver and manual for any TW limitations.
500 pounds is very low to add for things. Clothes, towels, kitchen appliances, toys, games, etc. If it is you and a spouse, close. With kids? Nope.