Yes, you can. Pt is distributed under the LGPL with two license exceptions that also allow static linking and incorporation of inline code from the Pt header files (i.e. C++ class templates).
The LGPL requires that users must be able to replace the LGPL code with a modified version. This is impossible for C++ code, where large parts consist of inline functions and templates. This requirement renders the LGPL equivalent to the GPL.
It also complicates static linking, because the object files of the program that links against a static version of the library would have to be made available, so the user can relink the application.
The special exception permits convenient use of the library in proprietary and non-GPL open source applications.
Yes you may. We understand, that in some situations, it is desirable to directly import some of the classes into a project, instead of linking against the framwork provided as it is. We do not mind if you do this, but can not give you the same support as for the framework. Still, we would very much like to hear from you! There are several projects that include code from the framwork directly.