Nothing big but just something I noticed when skimming through the code.

The following TLDs are not in the list of validTLDs ($_validTlds):
Generic:
asia
tel

ccTLDs:
bl
eh
kp
me
mf
rs

Future:
post
geo
cym

For more info:
IANA — Root Zone Database
Generic top-level domain - Wikipedia, the free encyclopedia