There's no one answer for all situations. But I'll give you some insight from years of recording:
Stereo Enhancers should be used sparingly and only at the very end of the process. They can cause all kinds of phase issues if you get too aggressive with them...and too aggressive is surprisingly moderate.
Gain should be dealt with first. I'm not a big fan of just normalizing because you can. Add gain to reach your desired level, but not because you're not hitting -0.3dBFS. Things can always be made louder later. Be gentle.
High pass before anything else because all those unnecessary low frequencies will cause other processors to react to the lows. And low frequencies carry much more energy than high frequencies...so they can overload other plugins.
Noise reduction should not have to be a normal part of the process unless you're doing something else wrong. Capture the sound with minimal noise to start. Even the best noise reduction algorithms (like Cedar or RX) will leave artifacts behind. If you find you consistently need more than a high pass filter for cleanup (maybe EQ in general), than rethink your recording process.
I never put reverb directly on a track...always an aux buss. Probably a carry over from my analog days with real reverbs (like real chambers and hardware plates). I also don't know anyone who mixes professionally who puts a reverb on their audio track directly. I also always EQ & duck my reverbs & delays.
EQ is a definite & so is compression. I like to EQ into my compressor. Some people like to compress into their EQs. That's a taste thing.
If I were handed a solo acoustic guitar recording to mix I would typically do this:
1: Use clip gain to get a good signal, but leaving a good 6-9dB of headroom. Commit track to lock in the new gain.
2: Add a HPF to clean up low end mush.
(I would typically pan instruments at this point, but we're talking a solo acoustic guitar...so it stays dead center).
3: EQ to taste (typically the same EQ used for the HPF)
4: Add some compression
5: I typically add a de-esser after the compressor to tame the harshness, Compressors can exacerbate finger squeaks and string noises and a de-esser can really tame that.
6: setup reverbs and/or delays on AUXs and send the signal (post fader) to the effects.
7: on my Master fader I may add a limiter to help me get volume and some sort of harmonic distortion (like McDSP Analog Channel 101 or Metric Halo Character).
This is a pretty typical process for me, but there are situations that require additions (like a 2nd EQ after the compressor or a second compressor in parallel). The track dictates what it needs based on its final purpose.
For instance: I'm mixing a band right now where the bassist taps his string between notes creating an audible "click" in both the amp & DI track. This is when I resort to noise reduction and have be using RX to de-click the bass tracks. It's tedious but it needs to be done. I console myself by reminding myself that they're paying by the hour
So, that's a case where I do have to use noise reduction, but that's not super common for me with music mixes. I use it all the time for dialogue cleanup for video...but that's a totally different mindset.
Hope that helps demystify some of the process.