I think the problem is that IceTouch XCode plug-in don't work well with workspaces, we have not tested it before, but when tested i found that this don't work well.
To workaround the problem i see two options:
Create a single project where you manually add generated files and turn off ARC for the generated files, don't add Slice files to the project, you can enable the plug-in to automatically link with IceTouch SDKs.
Or create two separate projects, the lib project with no ARC, no IceTouch plug-in, and Slice files that you need to compile manually, and Header Search Path configured. And the application project with must enable the plug-in to link with IceTouch libraries, and add also your library to "Linked Frameworks and Libraries"
Also note that your ARC enabled sources cannot direct or indirectly include Ice headers, or you will get errors similar to:
Maybe is just easy to not use ARC and wait until IceTouch include support for it to switch to ARC.
error: must explicitly describe intended ownership of an object array
int ICEInternalLookupString(NSString *, size_t, NSString *);
1 error generated.