Diminishing returns?

I love music and videos. I am fortunate enough to have a separate audio and home theater… which is ideal as they have somewhat different requirements and can get in each other’s way. But they can be combined effectively. Some good speakers and a good amp can raise the 2-ch part to a very high level of performance… ultimately limited by the receiver. But people’s lives change… more money, maybe move. Then those expensive speakers and amp can look like a tremendously good decision. Since my interest in music and home theater has persisted over my life, every time I reached for better gear than I necessarily could justify with my other components it has been a great decision in retrospect.

With that Denon it looks like the compromise is already made so might as well run with it, and you can hear whats coming up behind you in the films etc.
I run TV sound via optical through a two channel system set up for music, there’s no problem with centre fill from either end of a three seater but the speakers needed careful placement to achieve a wide listening area with a stable image and tuneful bass. I only have depth into the screen however, not behind me and they’re a bit too dynamic. If I set the volume to hear the dialog the sound effects get to neighbours annoying levels (we’re in a third floor apartment, temporarily) and I end up arguing with my wife about just how loud it needs to be. 

"...Sadly, this place is run by 2-ch fanatics (majority of them are deep into Vinyl or should I say anti-digital) Do you see the pattern, they have a one track mind….digital is bad, home theater sucks..."

I think you mean, luckily this place is for two channel enthusiasts. I still have my 60s and 70s LPs but I only listen to digital sources. 

Depends on resolution of your system to determin that point and how much you have to spend.

Ah yes, two-channel 'enthusiasts'. I admit to being one totally, but I still thought to suggested a center and surround solution (with better mains for two-ch use). It seemed to be what was needed per the O.P. unless I misunderstood. Sometimes it's not about what we want I guess.

I remember the days having to work it out for stereo and video in one system (adding TV sound in the 80s to a receiver). It was more challenging as the system grew and eventually separated.  These days I feel very lucky to have individual rooms/setups for high end two-channel audio, regular TV, and a home theater. It just takes time and if the O.P. builds carefully those items are very usable later. (plus I probably never sold a piece of audio gear in my life...)