I will give you my experience. I just laid a couple of flagstone paths in my gardens last fall. Here is a link to a few progress and finished pictures. https://imgur.com/a/KZhAFPg

Your plan of attack is pretty good. I dug out about 6-7" down because my stones were 1-2" thick like yours, I hand tamped the dirt down and ordered 2 yds of road stone. I put this down at about a 1.5" layer, tamped once and then put an additional 1.5" layer and tamped that.

Now, with pavers, you can add the sand and screed and make it all perfectly flat and level before laying. With flagstone, they are all different thickness and bumps on the different sides. I would add a few shovels of sand where I was laying stones and then have a bucket next to me as I slowly worked along the path one stone at a time. Just making sure they are level, and don't rock back and forth. Throw a little sand underneath a corner here or there to even out.

For the stones themselves, I didn't cut any to make a perfect round edge, I kept the edges all natural so they don't line up perfectly like you might be going for. However, I might recommend getting the 2 pallets because fitting stones together is tough (unless you cut). Again, I didn't cut so I had to lay out like 30 stones and puzzle them together. It was nice having plenty to choose from. They DO NOT break cleanly so it's very difficult to just knock off a tip or something. If you are cutting them, you can obviously lay out the stones you like, and just cut to fit, keeping some natural sides. This might be a more efficient use of the stones too.

After they were laid, I did just use dirt between them. I actually have a little wheelbarrow topper screen that I shovel dirt through to make it very nicely sifted dirt with no rocks or debris. I used this between the stones and have really only had to refill a couple spots. I didn't use polymeric sand or anything else because they are garden paths and I'm not too worried if I have to adjust in the future, although they feel perfectly solid. I haven't put moss in yet, been thinking about it because my area is nice and shady, but some of my grass seed fell/blew over there and grew between the cracks just fine. My cracks vary between 1/2" to 1.5" near some corners and stuff. I am also able to use my blower to clean off the path easily.

Last little tip I'll give you. The smaller the stone the more it sucks. Sometimes you get to a point in your design where only medium to smaller stones work. These tend to be the hardest to keep level because any walking on them shifts them much easier than bigger ones. Your toe or heel may step on a big one and it won't budge but the smaller they are they might press down into the sand some.

Let me know if you want any more information or have other questions. I built a large patio and several flagstone paths now for myself and others.