Without a working budget for any such "upgrades" this would likely be a futile endeavor.
Also what I'd change is almost certainly entirely subjective.
So the value of any of my suggestions would be questionable @ best.
That said...
I'd keep that Rotel RB-1090 power amp,it's a beast of an amp and I tend to like that sorta thing.

Next I'd lose the DAC & the speakers.
Why you ask ?
For the DAC:
1. I dont like DACs that upsample (I prefer to listen to files in their native resolution).
2. I dont do high rez @ all (redbook only listener here) so I tend to favor vintage r2r DACs as SOP.
For the speakers,I dunno what to tell you,other than to say they just are'nt the sorta speaker I lust after.
Also I've never heard a pair so I have no idea how they sound (did'nt I mention my input may be questionable earlier ???).
Also here is where I'll throw in a random question...
What is being used for volume control for this rig ???
If it's the volume control in the laptop than you are likely chopping bits off the laptop's output to the DAC (thus losing some resolution).
So what I'd do:
Track down and purchase a nice preamp with XLR outputs for that monster Rotel power amp.
Track down and purchase a DAC that is more to my liking.
Track down and purchase some speakers more to my liking.
Some of that sorta stuff I already have around here (preamp & DAC),but what I dont really have are what I'd consider "endgame" speakers.
And here's where budget would come into play for me,as what I'd go after definitely corresponds to how much I would have to go shopping.
Anyhow I digress for now...
And yeah I know
NONE of that was any help @ all,
LOL.
Sorry 'bout that.
Bret P.