Optimizing HT setup for Analog: Where to begin?

Greg - on the TT setup:  I have both the AT440/OCC and Denon DL-110 cart that I swap out.  I upgraded the feet a while back too.  The puffin is interesting with it's analog -> dsp -> analog processing.  In the end though, I don't really like to fiddle with things.  My next phono stage will likely be something from bottlehead.  My quarantine project was one of their headphone amps and I'm very impress with the build quality and sound.

On the topic of placement and room treatments - I don't have many options here - the room is multipurpose.  The good thing is that it's a carpeted and fully finished basement, but I know I can do better.    

Excellent! ...and here I thought this would be a difficult question to answer! HT bypass - I’ll read up on this. I didn’t know it was a thing.

fwiw, I do run the AVR in 2 channel mode on "pure bypass" which is a setting that removes the digital processing. Also, I when listing to vinyl I have it set at 2 channel only mode. Probably doesn’t make much of a difference though I’d guess based on the feedback so far.

I do also have a PSA sub to fill in the lower end.

Is the power amp or pre-amp the most important when talking about sound stage / depth? I have pre outs where I could send L/R to a more capable power amp if you think that would be a good option.

My main problem, is that I have to keep the 5.1 setup / avr. There really isn’t a way around this due to space considerations.  Also, as far as budget -- I'd like to stay just shy of diminishing returns in audio equipment.  I'd expect this to be around $1k, $1.5k, but i'm open to stretching.  My theory is to spend enough to remove all reasonable doubt :) 

Just curious - will the Phono stage in some of the integrates be better than the puffin?  Parasound P6, Peachtree Nova150/300/500, etc.  

And also, what's the difference between HT Bypass and a good 2amp/1speaker switchbox?  Aren't these functionally the same?