Alain Briot and his wife, Natalie, run fantastic workshops in the Southwest and West. Both were highly trained artists before they became photographers. Mark Adamus is another fantastic photographer--he teaches composition and post processing better than anyone I have met. I wish I was half as good as him. Other workshops I've greatly enjoyed were those of Nick Page, John Gerlach (Landscape + Wildlife), and Nasim Mansurov.

http://www.beautiful-landscape.com
https://www.marcadamus.com
https://www.nickpagephotography.com/workshops
https://www.gerlachnaturephoto.com
https://photographylife.com/jordan-photography-workshop

MacBook Air is the way to go. My daughter went through four PC laptops when she was in collage. Hinges broke, screens delaminated, keys stopped functioning, trackpad worked intermittently, etc. And those weren't inexpensive laptops. Since switching to a MacBook Air five years ago, she hasn't had a problem. I have used an M1 MacBook Air with Lightroom and Photoshop without any problems.

Magazine editors use calibrated monitors so that they know exactly what the image will look like when it is printed. If your monitor is not calibrated monthly, what the editor will see will be different from what you see on your monitor.

A DNG file will contain ALL of the raw image data that was in the original Raw file, but may not contain some or all of the non-image data that was in the manufacturer's original Raw file, such as focus point, the manufacturer's info for their interpretation of their raw data, the manufacturer's conversion of the raw data to a jpeg, etc. That is why the DNG file is smaller.

If you want a universal file format, use the TIFF format. However it will be larger than the any other format that contains all of the original raw image data.

It is interesting that Capture One can easily interpret a DNG file from a camera manufacture (Leica, for example) but will have trouble properly interpreting a DNG file that was converted to DNG by Lightroom. All DNG files are NOT identical in format. Some other applications may have a similar difficulty. That is why I always save my raw files in their original format and don't convert to DNG files. Storage is cheap and avoids frustration.

If it isn't broke, why fix it? What is it about your current system that you have a problem with? Is your gear limiting you or would workshops, photography courses, or travel be a better investment than new gear. DSLR development has ended because mirrorless cameras provide significantly more advantages in focusing, shutter speed, information available prior to shutter release, and vibration at low shutter speeds--even an inexpensive, used, fixed lens mirrorless camera is a better investment if your current DSLR is limiting you. If your gear is limiting you, consider that going from one DSLR to another DSLR is an insignificant an advance in usefulness compared with going from a DSLR to a mirrorless camera. Good luck with your decision.

For the best of both worlds, use rapeg.

If you care about color fidelity in printing, you should get a monitor that can be hardware-calibrated. BenQ has good options. If you don't care about color quality of your output, get an inexpensive monitor.

Return it!

You left out the most important information: What does he want to photograph and how will he share the images. For landscapes, travel, and family/friends photos, a good cell phone can’t be beat by any camera currently available. I know professional photographers who use iPhones because the image quality iPhones produce (possible with automatic internal AI processing) is not achievable with a camera without exposure bracketing and extensive post processing. Imagine your friend’s disappointment when he compares his camera images with his cellphone’s images.

Unless you are processing thousands of images at a time on a daily basis, you are wasting your money. The difference in processing a thousand images on you dream computer vs on a computer costing less than $2,000 will only be in a few minutes. Knowing what is worth doing is just as important as knowing what you can do.

Not dead; just in need of a visit to the doctor.

Snapseed is a great smartphone photo processor.

1. No front or back focus
2. Full screen AF points, even at apertures smaller than f/8
3. Histogram, clipping warnings, and peaking available on screen and in viewfinder.
4. No mirror shock at low shutter speeds

For landscape, f/2.8 is not useful. Also, 24mm is more useful for landscape than 35mm.