I can't seem to be able to design any map in photoshop without the lines being solid distinct lines. I've tried to design a map using the Brush, Stamp tool, even the 3d map maker in photoshop, using all sorts of terrain party images, but nothing blends smoothly once it's loaded into the map maker.
I'm using the correct size of 1533x1533 - 72ppi 16bit Grayscale, but I can't get it to function properly, and the blending isn't smooth still.
I've tried to blur the final image, and feather, but nothing makes the lines smoother. Any suggestions? Attached is a sample of one of my finished projects.

at some point during editing process you must've saved it as 8bit image.
hence the loss of color precision (quality) which can't be recovered whatever you do afterwards.
start over with a clean 16bit Grayscale and never save it as something else.

I had thought that I did, because starting over is a monumental project, However I will give it a shot.
Can I use 32 Bit to ensure even better quality or is 16 the best? And will the brush and clone tool even using a varied opacity function the same, and not create the lines?

32 won't add anything to the detail. and probably the filesize will be too big to upload.
No, I'd always go with 16-bit grayscales.

Rationale:
On a 300m high map you will need about 3,000 different shades of gray in the image to have a smooth terrain (since the 0.1m steps in the LiF terrain). More won't help.
8 Bit grayscale supports 255 shades
16 Bit has about 65,000 shades - that is far more than enough.

Now, that all makes sense, and I'll follow that but just to be specific here should we do a resolution of 72 as standard or are we talking 300 or 1440 ppi resolution at the 1533x1533

Also, do you ever have even minimal banding in your results? I see still a significant amount of banding when I even upload a base map. How does that transfer when actually generated onto a server? Is the land severely tiered also or does it smooth?

ppi doesn't matter. it's for printing.
what's "banding" supposed to mean?

Banding is the ridged that are formed when your texture isn't smooth as you drag a brush or copy across. I thought it'd go away with the 16bit, and it's less, but not enough.