It seems that you have not compiled your gtk with XInput-support. Please rebuild gtk and use ./configure --with-xinput=xfree for building the Makefile. Then do a make && make install. Then rebuild your gimp so that it uses this extendet gtk.
Yes, it generates button 4 and button 5 events.
read the section about Serial_Num
Read the section about buttons.
You can not use the intuos macro area, sorry.
Only Artpad / Ultrapad Macro stripes work.
Read the section about
Gimp Keys.
Yes, read the section about the Top... Statements
Yes, read the section about the Port Statement