BTW, when I even do whichpm JavaScript::Embedded it takes ages (18sec) to complete! 100x more than other modules.

Yes - I think it's just silently compiling the Inline::C code first.
IMO, the Inline config should specify build_noisy => 1, so that we can see what's happening (or, at least, that *something* is happening).
It also needs to specify a build directory something like directory => "$Config{installsitelib}/_Inline", in order to avoid the re-compilation issue cavac mentioned.
There's a bit to work through.

BTW2, my compiler complains that croak(msg)....

I haven't noticed that ... something else to check.

Cheers,
Rob