Gaussian Splatting can show in real-time features like reflections, fur and hairs and other complicated thing that takes a lot of time to render. You will need to do the heavy lifting only once and when the synthetic Gaussian Model is ready it can be shown real-time even in web browser. With these synthetic datasets you can research and make all kind of test for the Gaussian Splatting training. It gives you change to make 3D scans virtually that you otherwise wouldn't be able to do in real world situations.

You need a separate training software like Jawset Postshot or NeRF Studio to train Gaussian models from the images. Camera Array Tool can only produce data sets where the 3D Gaussian Splatting conversion then can be created. Datasets are made from rendered images and the Colmap data which are written in three TXT files. These contains information about camera settings, 3D coordinates and a point cloud data.

Yes you can. You can make all kind of camera array setups with this tool. There is even a pre made object called Interior Tower in Camera Array Tool which can be used for environment arraying like rooms or other 3D spaces. When making image dataset of environments we mostly use outward setting when creating the cameras. Interior Tower is meant to be duplicated around the room and then join all towers together then you can create cameras on to it pointing outward.