Yes, locally patched both issues, now runs fine. $wgExcludeFromThumbnailPurge is not defined in 1.17, made a check. BTW, it is a bit evil to exclude some extensions from Purge. Maybe there should be another action "Superpurge"?
Linker::link() was called statically in TranscodeStatusTable class. Created new Linker() and now it works. I haven't committed into svn, don't know if anyone cares of backcompatibility.
BTW, if I'd was an leading developer (who makes decisions), I'd probably make MW 1.16 an LTS (long time support) version for legacy setups and extensions.. Though maybe that is unneeded (too much of burden for non-profit organization).
Dmitriy