Micro Displacement how to make it to look better, or is there a better solution (5 questions) Recently I've been working on personal projects so I decided to give displacement map a go [I am trying to take images of wall carving, ornaments, or patterns and make it 3d, but I have so far encountered a few problems.

1.The surface is inacurate



What should have been smooth is too rough, and looks like a rocky mountain instead of a smooth sculpture

2.The original plane gemometry didn't seem to go away

I pressed subdivide in edit mode 1 time , add ten cuts
, then added a subsuf modifier pressed Adaptive, but still getting these result, and adding more loop cuts just seems to worsen the geometry and the mental state of my computer

3.Trying to figure a way to change textures

So this is the texture map and the displacement map

Since the displacement map has to be blured out in photoshop, the geometry added in isn't enough for the details, but then it seems to heavily depend on on the texture map to give details, is there a way that I can save the details and change the photo textures from stone to wood or something else? (The bump map only gives me details but since the geometry is not enough to start with without the texture map it looks horrible)

4.Is there a way I can apply the TRUE displacement, see and edit it in the edit mode?

5.Is there an another way to approach the same effect 

I have watched some videos on youtube such as
https://www.youtube.com/watch?v=Tsaa_D6CcSo
I think this is hard surface modeling(not sure), though some projects can be done by this method but when it comes to wall carving, the geometry won;t be that simple, sculpting may be a solution, 

but it takes time and skill to reach the decent level and look like the reference image, which is something I don't have as a programmer background lowlife freshmen peseant , and I don't know how to retropology yet.
Lets go from big issues to small ones. 

1.The rocky, jagged surface you're experiencing is a the fact that your displacement is too strong. Add a Math node, set it to multiply and put it between the displacement texture and the displacement output in the node editor. You can then adjust the second value to decrease the height, to make the displacement more subtle and thus convincing. 

2.The original plane geometry doesn't go away, it just gets subdivided more when you hit render. What you're encountering is the preview mode - in a render preview, the mesh is subdivided less to improve performance. That is the "Dicing scale" option in the subdivision surface modifier. The smaller it is the more detailed the mesh will be - both for rendering and preview. Decrease the dicing scale if the issue persists during rendering. 

3.The thing with textures is that they always add surface detail. By that I mean that certain surface imperfections are just in the Albedo, but not in the displacement. Those will dissappear if you use a different texture.  If you go too detailed with your displacement texture you'll eventually encounter the limits of whatever image format you're using. The basic displacement can stay the same, and you can slap a different texture on top without issues. Keep in mind tho that the displacement and Albedo textures tend to go hand in hand tho. Out of curiosity, why did you blur the displacement texture?

4.This feature is coming to blender, but not there yet. You can refresh the mesh by tabbing into edit mode and out again when you've made changes. 

5.You can definitly sculpt such detailed wall ornaments, although sculpting is quite different. It will certainly take more time to sculpt it, a micropolygondisplacement will definitly be faster to implement. Depending on your final sculpting implementation it might be more ressource intensive as well.