Agree with most of what has been said.....additionally, after you have made a few of the changes noted (emphasize
@Legrace suggestion about the SAS) you might think about a separate phono stage which might improve things over the built-in unit you have in the Yamaha receiver. Note that there are sellers who will permit you to purchase one, use it for a period of time, and then return it if you don't believe it made an improvement in your system! Not sure I am allowed to mention who they are, but you can easily find them on the web. This way, you can "try out" the ride before you actually commit to it, which is always nice! You will be responsible for return shipment, which will likely set you back around $35.....
Having said that, I really like what knots and gizzy suggest about your setup and room treatment. I can tell you from personal experience that a simple movement of your listening position can sometimes have a HUGE effect on what you hear! It's fun, cheap (as in $0.00), and will very likely surprise you when you hit the "sweet" spot! There's a lot more to be learned over in the Listening Spaces forum about this and some very knowledgeable folks, some of whom post in this forum, that will no doubt be eager to help.
Finally, I have to say
@homebrew made a most salient observation about a subwoofer......Now, I know subs aren't for everyone and no doubt about that HOWEVER, in my experience having a sub (2 for me!!) takes my system to a whole 'nuther level. I've helped others with this who were absolutely stunned at the difference in sound of their systems. As HB states, you will find your Paradigms taking a breath of relief as they no longer have to pump out the really, really low frequencies and can apply themselves to the more workable ones for a speaker their size. Oh, by the way, have you thought about re-capping the Paradigms? After 30+ years, I would if they were in my system! Should be really, really simple too.....
Good luck on your journey and time to have some fun.....listening.....that will tell you what you likely should do!