Is there a difference in sound quality when streaming TIDAL Vs CD player

I have not heard the Arcam so I can’t really answer your question about how it sounds vs a Parasound integrated.  I do have Parasound pre  and power amps in my two channel system and a Parasound 5 channel amp in one of my HT systems, but sorry can’t compare to something that for me is an unknown.  I will say that the reviews on the Arcam which I read after reading your initial post were pretty good, that Arcam is a respected company, and that for $3500, which was the price quoted for the Arcam, you probably have a top of the line, fine sounding AVR.  Some of the money spent on the Arcam went into making it a multi channel component, and if you don’t choose to listen to Multichannel, you are paying for functionality that is wasted.  Whether or not you prefer the House Parasound Sound vs the Arcam sound will significantly be a matter of personal preference.
You sound like you have what we call Audiophilia Nervosa,  a type of Buyers Remorse that is common in this hobby.  I am sure that you have a fine sounding piece of gear.  Relax and enjoy the music.

Regarding the Oppo connectivity issue: The 203 should have digital outs in every flavor m HDMI, coax, toslink, usb....I am not sure which one The Arcam will accept, but AVRs at that price will usually do it all.  I use HDMI to connect my Oppo 105 to my Bryston DAC3 in my 2 channel system , because I have a large SACD collection and Oppo can output the DSD from SACDS into an HDMI DAC such as the Bryston.  I find that CDs from the 105 into the same HDMI input on the Bryston also sound excellent, although I have experimented with the coax, optical and usb connections between the two components as well, the HDMI sounds as good as any of them so I’ve just settled on using that.
  In my MC system with the Oppo 203 I use HDMI into my Anthem AVR and haven’t really experimented with other connections 

What I can say is that I have an OPPO U203 also, and I've compared the sound from its DAC (via RCA outputs to a preamp) with the sound I got when connecting its coax digital output to both PS Audio DirectStream Jr. and DirectStream DACs, and the PS Audio DACs were superior to the OPPO.  Of course, as could be expected, the DirectStream was superior to the Jr.

I have the program Pguin, and use Synology DS218+ ,wireless to the Logitech , connected with the DAC of my Luxman D-06. The sound of the sacd-player of Luxman with cd, is more open and more dynamic.
For me the best is the sound of cd’s.. (The sound of streaming is detailful to, but i give it an 8 while i give a 10 for Cd.)

Hello, in short words "yes it is".
I am playing with Auralic -> Chord Blu 2xBNC (~720kHz) -> Chord Dave -> MC2600 (NOS tubes, old and great Telefunken and Siemens) -> MC302 all with Tellurium Q Silver Diamond) application between. The last change in my system was Tellurium Q Silver Diamond USB cable upgrade and it did tremendous job in increasing Auralic straming quality.
Enough to say it is really difficult to distinguish CD (Blu) and streamed WAV file in this config. Still possible and better on CD side but in therms of preference not comfort.
However, then streaming from Tidal the difference is significant. Especially Tidal HiFi and much lower for Tidal MQA. The MQA files have the ambition to catch CD quality but it is still just an ambition. In my opinion Tidal HiFi is superb for playing from cars, mobiles, and up to 2000$ fixed gear, Tidal MQA is for most of the stationary playing equipment, but it is not a serious source if your gear total is above 10.000$. Absolutely unacceptable for Hi-End solutions.
Personally I use my Tidal in my car, phone and as an excellent source of music browsing and searching. Yes, great as library.
Well, in fact, serious problem with the music in general is the loudness war issue. If you will compare DR7 to DR14-18 tracks you will find it much more disturbing than streamed material quality problem.
Please refer this info to Qobuz as well.
Spottily if for mobiles, causal listening and barbecue usage only.

Added: I noticed some colleagues try to use some degree 1-10 scale. Well here is mine at this moment:
Spotify: 2-3
Tidal HiFi: 3-5
Tidal MQA: 5-7
Locally streamed file FLAC: 6-9
Locally streamed file WAV: 6-10
CD: 7-10
Hi res files, SACD: 6-10;
Turntable: 8-10