Can Tango work with 32-bit device servers

That depends if you have any requirements on the MSVC runtime libraries? The cppTango shared/static libraries also use shared/static MSVC runtime libraries. If in doubt I would start with libtango_XXX_x64_shared_release.zip/libtango_XXX_x64_static_release.zip.

Also if I temporarily rename my current folders at TANGO_ROOT and put ones from the downloaded package there, will it be okay for CMake to build a working .exe for the x86 device server?

Should be okay.