You wrote
"emerge inkscape" does nothing but unnecessary dragging of new version of perl (I'm not sure why, though).
You need perl to be able to import TXT files, as this extension is apparently a perl extension. Most are python IIRC. That's why I put that dependency into the ebuild.
It's disabled in 0.44 official tarball, isn't it?
What is disabled in 0.44 is internal scripting, something different. For that, you would have needed perl AND perl development support.
No. Not really. I've mixed up "x86" and "~x86" USE flags in the past, but that shouldn't make any difference. I think?! I can't think of that as anything "special", taking into account that gentoo still has inkscape 0.43 marked as "x86" stable and version 0.44 for testing.
Even 0.44 should work on your system, but I'm actually out of town, at the moment, so i can only mail you this info. Hope it helps.
ralf