Seeking opinions on the Luxman PD151 and EQ500 combination

"wide channel separation and tight channel balance are cartridge performance measurements directly relating to good/better/best capability". Perhaps, but the numbers quoted by manufacturers are for an average sample when brand new. There is no guarantee that any particular sample meets the stated specs or that any given sample will retain those specs over a period of use. Moreover, we are never told how the measurements were made, whether they pertain to the real world of playing an LP, or not. Could it be that your perception of a correlation between channel separation, etc, and SQ are influenced by the fact that you know the specs in advance? Or that cost often is a correlate of those measurements, with manufacturers quoting the best specs for their top of the line cartridges that therefore cost the most (and sound best too)? I guess I am a cynic. There is nothing inherently wrong about your approach.

Just so you know, I am not an advocate of dust covers except to keep dust off the platter when the TT is not in use. When playing LPs, my dust cover(s) are somewhere else in the room, never on the TT or over the LP. This is because I think a closed dust cover creates unpleasant colorations. Not everyone agrees. You will have to make your own decision on that, so it is good that you have a removable dust cover. The key word is "removable", not just raised up for playing LPs. As to alignment, I think the obsession with it is way overdone, but I do try to be as accurate as my tools permit and leave it at that. VTA is a matter of taste, like cartridge loading. Go with VTA that sounds OK to you and you'll be fine. For me that means I level the TT arm wand so it is parallel to the LP surface. And boom. To further my nihilist approach, I do not think you can predict the sound of a cartridge from any published spec or even from the aggregate of all the published specs, so long as the specs are not obviously awful.

The Luxman PD 151 is a modern belt drive turntable, which you can buy new from a dealer without concern about its functional capacities. Whereas, if you invest in a vintage direct drive turntable such as a Luxman PD 444 or 441, you must also be prepared to deal with functional issues that may affect performance just due to age or mis use. Some of us do not have the intestinal fortitude to put up with that. If you do have the guts, then yes I agree a vintage high-quality direct drive turntable is certainly a way to go. As you know, I love them and own several. But it’s a whole different kettle of fish for a person who casually wants to get into vinyl. The OP might be better off with the PD151 or similar. 

Vintage Knob is also valuable for vintage turntable information.  This gives me an opportunity to add to my previous statement about the underwhelmingness of the ARC PH9; the Luxman EQ500 is sure to outperform it, in my opinion. Furthermore, you can consider a TT and a phono stage to be two entirely separate items. 

If you’re still using the PH9 for phono, which is not clear from your OP, I can only say that it was not well regarded when it first came out, one of the few AR preamps that was unloved. I heard it in my system and unloved it too.