Can I copy parts of applications that are not specific to the invention?
Probably, but maybe not.
The key issue comes down to whether your copying would infringe the original author's copyright. Whether the portion you copy relates to the technical implementation or relates more to the scope of the patent (what you call "lawyerspeak") is largely irrelevant to this.
Is there copyright in the text of a patent?
Most likely. Assuming the text is original, there is no reason it should not get copyright protection just like any other literary work.
Would your copying infringe the copyright?
Probably not, though there is no clear law on this. One theory is that any copyright on the content of patents is so limited in view of the purpose of patents that any enforcement would be practically impossible. However, it seems no one has really tested this in the courts.
What are the alternatives?
Even if you would be infringing by copying, the practical risk seems vanishingly small in my opinion. Who would bother suing over copied patent text? But nevertheless you may still want to avoid such a risk.
In the US, you can simply incorporate the content of a previous patent by reference. This has the effect of formally including all the matter disclosed there into your application without having to expressly set out the wording. Since you're not copying the wording, there is seemingly no risk of infringement.
Alternatively, it is well established that there is no copyright in the ideas that are expressed. If you copied the ideas, but used your own original words, there would be no issue.
Most of the analysis was taken from an Alderucci paper. Wikipedia has a pretty decent discussion too.