Do I have to use a streamer/renderer to play music from an NAS?

You have the basics above. I’ll just add a few comments.
First, think about the tasks - you need something to catalog and let you browse and select a file to play. Someone mentioned ROON, and i think that happens to be the pick of the streamer litter. Next, you need to get it to the room your stereo(s) is (are) in. This is any old ethernet network - not Wifi preferably (although it may work). Next you need to terminate the ethernet, convert it to either USB or SPDIF and provide that to your DAC which may be in a receiver or may be stand-alone. There are bunches of these, one by ALLO based on Raspberry Pi is excellent for the money.

Note that the digital signal DOES impact sound a lot, for good reasons, mostly 1) jitter and 2) noise, which causes 1) (jitter). Its HUGELY important. I was shocked.

Consider both what you need to get ot to play today, but also what you want for the future. I want a single server with a great interface for all my music, radio, streaming subscriptions etc. This will be ROON on a dedicated server (NUC/ROCK/custom linear supply). AS long as i can make that electrically and mechanically quiet i do plan to have that as part of my main system and drive my DAC via USB directly (well, galvanically isolated, but that’s about the noise bit).

Commercial streamers like SONOS and Bluesound simply combine some of these functions in the head-end and others int he remotes. SONOS, by the way, sounds awful in the context of true high-end. I was also shocked when i first heard that in a very good system. Switching ti CD was a relief.

I need to look up audioengr’s roll-you-r-own components to see what its about. I don’t think i’d give up ROON though.
G

I run a  Synology NAS that I keep on the first floor on my wired network running CAT7 cables and through a few gig switches. I have two stereo systems the main uses a PS Audio Directstream and one a Perdfectwave DAC, both connected to the network. All the computers on the network have JRiver installed as well as a tablet so I can control from anywhere. The software seems to work well (Windows based computers) and the SQ on either system is more than acceptable. Have not fiddled with ethernet cables outside of upgrading from CAT5's as I feel it is just data at that point and not sure how different cable would make the data better.
My  $.02

I have also a Synology NAS, an he is wirelessly connected to my Logitech Squeezebox Touch ( little, but very good) and this is digitally connected to the DAC of the Luxman D06. On the Pc.,i use the app. IPeng. (To save the music). Along my iPad,i can play my recorded music.

to Steve:
Why do you advise against *lossless* formats like FLAC/ALAC?

They are, after all, lossless, and after reconstruction are identical to RAW. And, I have compared and heard absolutely no difference. I admit i have not compared many times or particularly carefully since (danger will robinson!) i knew what the result would be :-)

No, on low powered computers or slow disks i could see it causing more power noise or even jitter/errors, but that would show up.
On re-reading your post i wonder if there is a subtlety in it, you actually say "avoid ripping to ALAC or compressed file using itunes". Is itunes somehow the problem(how?) or ALAC, which, after all, is lossless (mostly DPCM)??  TIA

I really appreciate the kind respnses. I am still a little confused.  Lukaske, it seemed from your response that your NAS is connected wirelessly to a Squeezebox, which I assume functions like a tablet, and that the NAS is then connected to your DAC, with no other renderer.  Is that correct?  If so, which Synology do you use? That is how I am considering setting up mine for now, adding a good streamer/renderer as I save up more money.