As a fellow metal head, good luck. Also in my 40’s so we probably listen to similar things and the recording quality of most of it is hot garbage.
Short of changing what you listen to I would look for a vintage or semi-vintage receiver with something called a Loudness button or even better a variable loudness dial. This is not really “audiophile” but really helps these recordings sound better. You can leave it off most of the time but flip it on when you’re playing some especially terrible recordings. Don’t be afraid of the treble dial either, nothing wrong with adjusting that dial.
Marantz or Pioneer SX (like the SX-850) would be worth considering IMO. Don’t be scared of wattage ratings, 50wpc out of one of these should be more than enough for almost any speaker. Getting a well priced external DAC like a Schiit Modi is very simple.
Avoid Klipsch, horns won’t help at all despite how generally well reviewed the RP-600M are reviewed online. I’ve had some luck with Monitor Audio (Silver 200 5G) and slightly older Dynaudio (Focus 110a) and Paradigm (Studio 20 v5) speakers but you should take some songs to your local dealer and give some different speakers a listen.
Worth it maybe to buy a couple of sets of used speakers and trying them out in your house and then flipping the ones you don’t like.
As always your mileage will vary this is just my personal experience. If you have a hard concrete room with clay tiles there’s not going to be much hope for you.
The Vali outputs are variable, controlled by the volume knob.
If you wanted to plug your TT into the Vali you’d still need your phono pre-amp (RIAA stage). Then the outputs from Vali to the line-in for your Klipsch would still work, you’d just have to manage two volume controls.