Hi Tommy18938;
Welcome to the forum.
If it is already trimmed, and doesn't fit on the rack you should be able to bend it so that it will fit on the rack. You can cut the brisket. If you haven't done so already, watch a few videos of trimming and separating the brisket into two cuts. The thing you need to be careful about is to make sure the brisket or the butt does not touch the back wall. If it touches the back wall grease will flow down the wall, onto the element and cause a fire.
It is alright to use the lower rack for the butt while the brisket is on one of the upper racks. Use your experience from your previous cooks, to get an idea of how long your cook will take. I find that briskets generally take longer than butts. The timing depends on how long it will take for your Bradley to get up to your target temperature. Once it gets to your target temperature the timing shouldn't be no longer than it would take to cook the largest piece. For example, if you are smoke/roasting just a brisket, it may take two hours to get to your target temperature, and another 14 hours to finish - for a total of 16 hours. If you are smoke/roasting a brisket, and a butt; it may take 5 hours to get to your target temperature, then an additional 14 hour for the brisket to finish; your butt should also be finished, if not sooner - for a total of 19 hours. Keep in mind the times I'm giving are just examples, your times may be longer. If you find yourself running short on time, you can transfer one or both pieces to the kitchen oven.
When smoking large fatty cuts of meat, change your water bowl at least every 3 hours, during the first 6 hours. Even if your water bowl looks full, it is most likely filled with fat.