1) Twitter Url: Use siteurl instead of long URL (use site URL)
So you want to always show just site URL no matter what image was shared? It is possible, but in this case plugin will not share selected image, its will always share just your site default image.
2) Second Provide options for reset images by js code.
Sorry, don’t understand this point. What you need to reset?
3) Facebook cache come because every time you need a unique name of the image.
Yes, this is how Facebook sharing works. Its cache all shared links. To get around it you can add unique parameter to each shared URL. This will force Facebook to clear its cache. I can help you with code snippet for this if you want.