I am one of the few that has one too. They are an odd bird. We have replaced the folding mattress with a real one, but your probably younger. You might not need that level of cushion. I was so proud of my mod to hold folding chairs, there is a picture I up on here with it. It makes lots of usable storage. My tent would fall out of the top, because not all the screws are there. You will see from the inside the "buttons" that cover the screws. My unit is missing a few. For light we have shower curtain rods with blankets to keep the bunks dark. Do yourself a favor and make a ladder out of a piece of wood and cabinet door handles or something so your kids and get up and down. Otherwise they put their feet below the TV and destroy that. Yours is 4, but he won't be forever.
I put in some USB chargers behind the TV, ran the wires down to the fuse panel and added a fuse. We added a electric hitch jack.. HUGE upgrade. You will find out why. We also have an R-Dome, its the best way to keep the bugs out of the trailer. My daughter, not so politely, asked if I would clean her ceiling on the top bunk from the bug splatter. I also added a quick disconnect for a Coleman grill on the back of the trailer. There is a pre exisiting fitting so it was really easy. My kitchen window is how we pass dishes as a result.
Get a outdoor plastic rug, mine is 9x12, its your number one way to keep the trailer clean. In TX, there are birds that warble all night if there is a light, DO NOT CAMP THERE with hopes to sleep in the tent.
You will love it, we love ours. I almost took the bathroom door off just because off my shoulders. Also, call Forrest River and get a 2nd year warranty for $150. You will be amazed what breaks and when or why. At least you won't have to pay for it. I just climbed down off my roof because I am reattaching the A/C blower motor. The bolts came out. Not FR problem, but amazes me nonetheless.