If you look at your full size image, the coma on the stars around the periphery will point the way to the center of collimation. The coma also blurs the image; it gets worse the further you get from the center of collimation. That is simply a "feature" of most apertures, to include refractors. So even a refractor will require an edge flattener. (And an edge flattener for your Newt would be way cheaper than even a cheap imaging refractor.) The advantage of reflectors is that they have no chromatic aberration; even an expensive apo will have CA around bright stars contend with. Just no diffraction spikes.
There's nothing wrong with being a connoisseur of apertures (or radios). I own two telescopes—an f/6 Celestron C5/750 and an f/15 Skywatcher 180 Mak. The Celestron was never made for AP, so it has severe, uncorrectable edge coma. And the Mak is great for planetary, but it's too slow for easy DSOs (and my mount isn't up to the tracking task at that focal length). So I mainly use camera lenses for AP. Their speed (all between f/1.8 and f/4) is their advantage. The only AP-specific optics with focal ratios in this range are a RASA and a Newt astrograph. But the RASA is massive—hence my desire for a Newt.
I checked again with my laser.
Obviously a bit off.
But I adjusted it. Both times the dot was in the crosshair on the focuser side of the laser.
Problem is, who knows where it is after hanging my DSLR; I'm sure it goes out of alignment.
A good focuser is 3-500bucks. Thinking a Moonlite with the required LXD55 adapter to get the backfocus. Then mounting and re-aligning. Might be easy? I don't know. Can the tube itself support all that weight now?
What about the dent?
Using the finest straight edge.
These things add up to why I'm considering a used Refractor. I've seem some great images with the William Optics refractors for a reasonable price.
And you're obviously right, both would need correctors. Coma or field flattener. So that's sorta a moot point in the price comparison. Unless the field flatteners are twice the cost. I pretty much refuse to buy new whenever possible.
I guess in the end, I don't really know what to do. The newt is good for visual on the moon when people are over. Seeing the closer planets is fun, too.
But it just seems I'd spend a lot of effort getting the newt to decent (read-newbie) AP level.
Again....I'm a very new newb so I appreciate the input and advice.