What is that you are trying to accomplish by adding and/or replacing? Is there something specific from that list that makes you unhappy?

You could get better receiver or if you have higher budgets you can get AV separates (AV preamp surround processor + multi-channel power amps).
As for receiver choices, I would seriously consider the new flagship Marantz SR8012, Anthem MRX1120, Rotel RAP-1580, Arcam AVR 850, AVR 550, or Denon AVR-X8500H or AVR-X7200WA. As for AV separates there are many choices out there deepening on your budget.
Room treatments and better room EQ or room correction or calibration will help achieve to better sound and more immersive surround sound eg Dolby Atmos, etc. Especially in surround sound of home theater environments, a good room correction or room calibration softwares eg Audyssey, Room Perfect, Dirac Live, ARC, etc is crucial.