Looks like your last example is very nearly fine, you just need to run that edge connecting to the cylinder at the centre of the spiral into a different edge of the cylinder, rather than just straight into the middle.
I dunno about Max, but in Maya, I can set it so that any edge at an angle higher than certain degree set for hard-edge smoothing thingy. Can you do similar thing in Max ?
Soften your edge normals in that loop. You can do that through Normals > Soften Edge. Also, in case you ever do a Duplicate Special, make sure to merge the vertices in the axis loop before doing that.
I don't understand what you mean with seams, but if you mean the edged edge of your circles, it should be easy to fix, just select all the UVs and apply some relax on them, that should do the trick.
there is no need to delete edges: under the "loop tools", there is an "AutoLoop" option which you should turn off, then select a vertex for the highest point, finally select all edges you want to curve and hit the "curve" button.
It think it wise at this stage to re-evaluate your edge widths. At this point a lot of the razor sharp edges are just not going to translate into smooth transitions at all when you bake it down. Something to really watch out for.
As mentioned, probably need to work on the grip some. Looks off. The rendering also, a lot of the edges look too soft I guess. In your first picture the edges look considerably better, maybe a lighting issue?
You can extrude the ring of inner edges in on XY and with all of them still selected merge edges to center Also, you can set materials in unreal to be two sides, so you won't have that issue.
That's my workflow for mapping edges like this to a horizontal tiled texture: 1. I select the edge faces 2. I flatten map them 3. I use my script to align them 4. Done :)
Oh okay, so I need to bevel the edges of the lowpoly, but what makes the bake so low quality, like really blurry/pixelated. And how do i fix uv splits? By making the edges soft?