Expert Advise Needed on Streamer - DAC combos.

I am new to digital audio.  It was overwhelming at first because of years with Vinyl, then CD.  I love Music and unfortunately I have expensive ears.  I am over 60 years so when I made my DIY Speakers I gave it a strong top end with a 1" compression titanium tweeter with a butt check horn.  They are sounding great with a Google Chromecast and the old Crown DC 150A, SL1 Preamp.  I can tell the Chromecast is missing detail but is getting full frequency.  I had a bad experience with a Christmas Present to me which has made me a bit gun shy  of digital products. 
 I purchased a Bluesound Power Node 2i .  I was disappointed with the sound compared to what I have now.  It was a well made product and the Bluesound app worked well.  The Amp had plenty of power at 60W.  
Here was the problem.  Accuracy of the lower brass instruments on my system. Compared to the Chromecast device  (Which should not have been comparable) the brass instruments sounded narrow, no fullness, boldness, no rich tones.  This was especially noticeable when comparing the "White Tree" sound track from Lord of the Rings.  The old system crushed the Bluesound with Dynamics, thunder lows in comparison. (My speakers do 30HZ or lower) 
I compared with direct to router, Bluetooth. same result.  Bluesound support said that it is just 1's and 0's. (I thought no, it is how you process the sound from there!) The vendor I bought it from took it back, no questions asked. Their tech support could not explain it. 
So here I am trying to beat a Chromcast device and 45 year old kick but equipment. So funny!  I am to the point thinking that the DAC in the Bluesound Powernode was not good enough for what I like in sound.  Fred next door might love it.
It was extremely detailed, completely silent between notes, separation was good, voices shallow same as in the low brass, trebble was crisp and clear.  Was is the DAC? 

Questions now.  There are people I admire on this forum that are literal experts on sound, hardware, DAC's, you name it with audio. I need some opinions and guidance.  
1. My budget is $2,000 for a DAC and a network streamer device.
2.  I am thinking the Bluesound Node 2i streamer is good?  What are your experiences with it?  
3.  Does an external DAC make much of a difference?
4. What other streamers in that price range is competitive or better in someones opinion? And why?
5.  I have been looking at Innuos Zen mini mk3 Music Server as a possible upgrade?. (Competitor to the BS Vault)
6. I have been looking at the Shiit  Gungnir  DAC to match up with a steamer and also be able to take audio from an external SSD USB HD. (If I do not get the Innuos) 
7. Does anyone have experience with the Shiit Gungnir mulitbit with the Bluesound streamer, or other competitive product?  I have read many good things about Shiit and want to buy American and a company with top notch service. 

Your experience,  advise, recommended products in my price range is very much appreciated.  It is a rare to have this opportunity to get great advise without pressure to buy something on the spot. I very much value everyone in this forum.  Thank you!  Paul