Responses from toetapfactor

Mcintosh 501 monoblocks vs. 402
IMO I agree with Macdadtexas..Pass labs on the top of your list with the 3.6 speakers..McIntosh is just too muddy and slow 
Eggleston Andra III vs Revel Salon2
IMO, your discrition of the Salon sounds more like the Andra..Ive listened to the Salon2 many many times with all types of gear..Always thought it was too detailed/bright and non musical...Andra 3 is a slam dunk for me.. 
Amp for Dynaudios
Guitar amps (either tubes or solid state)and their likes or dislikes dont apply to 2 channel stereo.I was a touring guitar player for 17 years and use a Solid state amp driving my Dynaudio 
Dynaudio C-4 or Revel Salon 2
Rtn1..Listen again to Dynaudio..C1 and above..The C4 will stand toe to toe with anything you just listed and come out the winner against just about all of them..You dont get it thats fine but the C4 is just flat out a great speaker 
Dynaudio C-4 or Revel Salon 2
The C4s are the winner for me in this shootout.Ive listen to the Salon numerous times,very non involving/ almost sterile and certainly the case compared to the Dyn C4s IMO.If you already like the "Dyn house sound"which BTW I dont think that exists... 
Speakers to compare to Dynaudio Confidence C4
IMO If you have listened to and enjoyed the C4s seems youve answered your own question 
Jadis JA-30's What Pre would you consider
Jadis JPL..Been there ,done that 
Avalon Opus with Marantz PM-11S2
I agree with Pdreher,garbage in /garbage out with that Marantz pm 11.I would suggest holding off and saving some cash,If going S.S Pass labs would be a nice choice,Ive owned a few ....but back when I had Avalons I ran Jadis tube gear with great su... 
anyone had a listen to the b w 803d's
Yes, a few times and they never get any better...An old line with an old sound...When it comes to B&W there are better speakers at every price point 
Should I Try a Tube Preamp?
IMO, I agree totally with Grannyring..speakers first! 
Harbeth vss Dynaudio
No brainer,,,Dynaudio C1s..but its really not a fair comparison as the Dyns are in a totally different league,IMO 
Sophia 2 with Plinius?
I tried a Pass X250.5, but found it to be a bit to dark sounding for my taste Thats a new one,pass being dark,huuuum. Try another listen..Most use tubes with Wilson sophia 2s 
Best cover songs?
Your gonna miss me/ Lazy Cowgirls(13th floor elevators)