First off, please have a look at your post. Can you read your quoted input file well?
Please have a look at this post with suggestions and guidelines for posting in this forum, which also explains how to quote files correctly so that the forum software does not try to interpret symbols as markup.
This does not make sense to me. If you don’t want surface reconstruction, then don’t have a surface. Where is the value in trying to force a system into a state that it does not “want” to be in and then extract data from it?
That said, why use a wall potential? Why not just wipe out the forces on those atoms with fix setforce (after selecting them through defining regions and a group) from that? The wall potential would be like placing your system into a vise. Is that what you want to model?
Why the (complex) python commands? Why not just use equal style variables?