That year didn't come std with a windshield, nor a rider backrest; those are in the plus side, although the crack may need attention. If the crack is more of a stress check near the mounting screws, it is likely stable. I had a similar issue on my CVO Road Glide that HD would not replace, although it lasted for the 4 years I owned the bike. Minus the "primary muffler" is a good thing, but it will make the exhaust note louder; pictures would be needed to express opinion on the secondary muffler. You can probably find someone's OEM takeoff that would sound good with the set up; it would need to be off a base or -S model to fit without changing the mounts (assuming whatever aftermarket exhaust retained the original mounts). If, indeed, the tires are original, they are now 11 years old, and that would be a significant expense.
The front tires likely have adequate tread remaining. If the rear tire is original, the center is worn down to the wear bars and the outside has good tread depth. If the tires are not weatherchecked or cracked, I would ride them and keep an eye on the sidewalls. The rear tire will wear down in the center way before the sides. We regularly ran to 14 to 15,000 miles on the rear Kendas, as once the center wore quickly, wear distribution would bring the sides down. That stated, the tread depth is missing and has high potential for hydroplaning on water-filled roads. (BTW, tires are a very opinionated and emotional subject on this forum.) Tires with mounting could easily run $800.