Lighting is first.
Rake lighting serves two purposes 1) reduces glare 2) enhances the texture of the canvas or oils.
You need good quality, soft even light. The more room you have to backup the light the less critical the light source.

Lighting options are going to be space you have and size of the art dependent.

Longest focal length space allows, reduces the "angle of incidence" to minimze glare and has less distortion. (No wide angle zooms)

Any prime portrait lens. Manual focus models are fine. Most prime macro lenses over 60mm are good choices too.

Your budget doesn't quite reach the full frame cameras. A used Nikon 7100 is a good start.

For working tethered, Digicam Control, free software, and a color correct computer.

I got a letter denying my submission around January with weeks given to remedy my proof of purchase documentaion, Adorama receipt. The letter went unopened well past the deadline.

You can see in the top image, the light is bothering the subjects eyes. And you have some glare on her skin. I'm guessing you shot this with a kit lens, I'd prefer longer focal length and faster aperture. You can crop in tighter, particularly at the top. A CPL shooting in this light is also useful.

Below her cheek in the second image you picked up a green cast. A processing artifact?

Portrait vs environmental protrait. Like in front of the hedge you have you subject in a controled portrait type background. The brights and shadows of the hedge are still not ideal. With the others the backgrounds are all distracting. You're tight but the backgrounds are there. I suggest switching to working on environmental portraits. Make the background part of the story, color, parallel story content, juxtaposition. You can't just ignore the content behind the subject.

Tough time of the day to be shooting.

Look up Nick Fancher's content.

Wait, they give them an unfamiliar device to interact with while they take an educational tour? The "researcher" does nothing to account for the inherent distraction. Why not give the control group a puppy? Is the device the issue or photography?

Let's go down the road aways. Think about the vacation you took 10 years ago. Now correlate those memories with the photographs you occassionally view. Yeah most of us have weak recall.

Last year. TSA asked I open my carryon containing a tripod. But I also had a camera bag and agents were guessing tripod before I got it opened. I think it was experience TSA eyes verses new guy. Minor delay.

On some of those small commuters you might need help storing the tripod during the flight. But the job gets done one way or another.

LR or Photoshop?
Do you save your files in original RAW or convert to DNG?

Explanation:
Lightroom keeps all edits in a "sidecar" file that Lightroom associates with the original.

I prefer to save original Camera RAW, NEF in my case. If it is NEF I know it's the original file because Adobe does not write or save back to an NEF file!

Lightroom Catalogs are a great way to store and backup your images. Just don't do any reorganizing or editing outside Lightroom's file system. Go to Photoshop from Lightroom, right click "edit in" When you save it will create another file in your Lightroom Catalog as a TIFF or DNG (set in preferences), regardless if you used destructive edits in or not. If you converted Camera RAW to DNG and save back to a DNG, Photoshop will add "edit", Edit 1, Edit 2 to multiple edits. ACR, Adobe Camera Raw, is also nondestructive. When used a a filter inside Photoshop, I'm unsure. But in my/Lightroom's file handling it isn't relevant. When you reopen a layered file from Lightroom back to Photoshop, you get an option of the original layered version or the Lightroom "flattened" version, Lightroom never sees layers. Any edits to a layered file in lightroom are in a sidecare file. You can't carry those edits back into Photoshop as the original layered file. But you can open the original layered file back in Photoshop and after another save copy the settings from the previous version.

I hope that explains how it works.

View Nx-i

Merrel Moabs, shoes or boots. I wear 13W. I find them true to size but they run tight. I don't always wear wides. I've not found wide width Merrels needed in sandals or boots. I have some good Keen waterproof boots that aren't wide. I don't like them as much as my Moab boots. I have waterproof hikers from Dressports? 13 W. Very comfortable.

(I'm heavy 240lbs) I need to daily alternate hiking shoes to avoid various issues.

It occurs to me you might have hit a missed labeled pair(s)?

On the low priced brands, HiTec aren't bad. Easily better than Timberland and a number of other common brands.

A long time ago I had a good pair of New Balance hikers. Other than that pair which I have tried to replace often, they never size right for me. Maybe just what you need?

The only reason I would use a camera generated jpg is for distribution from the field.

You are experiencing an anomaly with your jpg engine. Either you are wrong, have really outdated software, or your current software is setup wrong.

I have a Nikon D750, D800 and D810. I trust Nikon engineers to get it right. But you have multiple elements in each of these cameras impacting tone graduations.

The larger the pixel the more accurate photoelectric light reponse. So pixel to pixel changes are likely more accurate. The higher pixel density sensors, where it's apparent that high contrast changes create sharper edges, I assume the graduation are smoother. I haven't seen the Nikon engineers sacrifice image quality going to higher pixel counts. Some photographers may have the opinion the sharper images of modern cameras aren't as aesthetically pleasing, that is an issue that belongs in post processing. It is not unusual for me to lower contrast in my images.

Then the antialias filter on my D800 appears to soften graduations as compared to the D810.

Plus you have to consider whether a particular lens delivers light to the sensor accurately on the scale of pixel density. Without a doubt I have lenses I use that negate the D800 and D810's higher pixel density. The first example is my 70-300mm VR. I think the sharpness is maxed out before we get to the D750's 24 MP.

"based on all the settings" this can be confusing as many setting are for the JPG conversion, JPG engine.

RAW is the totality of the sensor's capture. We are always looking at an interpretation of that RAW file and so some settings are applied either by user choice or automatically. No monitor or printer has the ability to display RAW, displayed is always an intepretation. Nondestructive edits are instructions to mapping the RAW image to a JPG.

A map might be a good analogy of the difference between editing a RAW image or editing a JPG. Thinking of the RAW image as a three dimensional map with all the side streets, alleys, dirt paths and the JPG a less confusing amount of detail, just the streets in two dimensions. If you want to bring out the intersections of the streets in the JPG, from the JPG you don't have that data anymore.

I cover events with Tamron 24-70mm and 70-200mm f/2.8 zooms. Great lenses. Do I really need sharper cleaner images? Likely not. But if I'm going photograph a specific subject. I will use a prime first. My selection is limited to a 50 and 85mm, plus 60mm and 100mm macros.

If my resources were exhausted and my gear gone, I'd try to scrape enough to get a good camera body and a 50mm.

Correct exosure leads to better image qualty. The definition of "correct" may change with the ability of the individual cameras' RAW images.

Shooting with intent is best. Keep ISO low, expose for highlights, know the more you need to lift shadows the more noise suppression you need to execute in post.

Professional looking images do not get there by accident. And you still need light and line compositin.

Even your D3300 would appreciate better lenses than a 18-200mm. Compared to quality lenses they are soft.
Your 50mm should be showing you the difference.