A:AnswerIt depends on what you mean by “connect with Bluetooth”. If you mean connect the TV to the AppleTV without HDMI, then no. That is not something an AppleTV can do regardless of what TV you buy.
A:AnswerWell that would require something that understands PowerPoint. Just showing images on a USB is different, as that's just reading files (plenty of standards/protocols for that), but cracking open a proprietary format/actually running the slides requires an interpreter for that format as well as a processor that can run the PP slideshow.
Alternatively, you can create your PP slideshow as an industry standard video file (e.g. "Save As..."-->"MPEG-4 Video (.mp4)"); that format can be read by this TV from a USB drive. If at the root, it will detect the MP4 file automatically and ask if you want to play it; otherwise, it will allow you to browse the USB drive to locate a particular file.
