2) If you are working in a cellar or outside where you can dump the bar onto the ground (and you practice on how to do this safely) so that you aren't worried about safeties, self standing squat stands could be an option for you.
3) Based on your goals, it seems like a good plan. Extending the weights and dedicating those three days to just resistance training will help you with the building muscles and your low and moderate intensity cadio will be more than adequate to ensure good cardiovascular health. The high intensity cardio would increase fat loss, help raise lactate threshold to allow for even higher intensity work, and help you build speed, etc , but since you are already past goal, do not care for high intensity work, and have not stated speed as a goal, for you it not only does no harm to keep it out of your program, for your goals, it really doesn't add much IMHO. It would help raise your high end work capacity, but your increased weight training if progressing properly will also do that.