Hello Pam. The R400 will work great with your computer and powerpoint! Just plug the USB into the computer and start the presentation. The forward and back buttons will go through your slides.
The USB receiver should have come with the remote so there is no need to purchase a separate receiver. The receiver does get stored in the bottom of the remote, I would check that first. If it's not there then I would recommend exchanging the product.
no, this remote does not control the mouse, but there is a model that will, I don't remember the model number but I looked at it while getting this remote, as you know it's more costly.
Left is to start the presentation or stop it (go from presentation to computer screen page and back). Right is to blacken the screen and turn it back on again.
Not 100% positive here, but I would assume that if your tablet has the capability to accept a USB port, then yes. You may need to get an adapter to convert the USB into a micro USB or something to that effect.
Probably not. But there are Bluetooth apps between phones and tablets. I honestly would go with a wireless display for the tablet and control the show from the tablet. Look at the screen beam mini 2 as it works with most andriod devices!
Hello, Unfortunately, you cannot use the R400 with a Cox cable box. It is a presentation remote that works with a computer using PowerPoint. Logitech does carry a variety of universal remotes, here's a link: https://www.logitech.com/en-us/harmony-universal-remotes.