2 things that helped me with my cross were, first, creating a new CStimer 3x3 session, but instead of putting in a time, put in the number of moves that it took you to solve your cross. This will give you an idea of how much you need to improve. After doing that about 100 times, then take unlimited inspection to find a good cross solution. If you’re not already, becoming at least dual color neutral (if not full CN), will help this even more. The second thing that helped, and continues to help me improve my cross is just doing cross solves. Only time your cross, then try to make it even faster and more efficient.
For F2L, you should try watching example solves (including the ones here on the forums) to find more efficient solutions for certain tricky cases. Then, you should try to implement these algs in your solves as often as you can. As you said, reducing pauses is one thing that I think holds a lot of people back, including myself.
Obviously, learning full OLL will help you get better, but make sure you learn good algs. (Make sure not to have any B moves, and RUF and RUMr are the best movesets, so make sure to have as many of your algs as possible use these moves. RUS can also be good if you fingertrick it the right way.) For your PLL recognition, doing solves should help you get faster. To get better at AUF-ing, you can setup the cube so that you have a PLL with no AUF at the end. You should then find a sticker (preferably on the front face) that is solved. From now on, before solving that PLL, you should look at said sticker, then figure out which way you will have to turn the top layer to solve that sticker. That is what your AUF will be.
Hope this helps! I was in your shoes about a year ago, and all of these tips from various different people/places helped me to get sub-17 today.
