i am the newest member i especially created the account for devon ke dev mahadev discussions
the show has been great in terms of acting portraying things etc etc and i too watch it daily however as far as the question goes the story has been messed up already although i don't mean it in any negative way
1) Regarding Maha Shiva ratri
no where in the sources it is mentioned that shiva granted boon to chandrama on that day. widely held belief is Shiva manifested in the form of linga to test brahma and vishnu on the midnight of that day that's the reason people perform rudrabhisekha ro shiva linga at midnight on that day.
http://www.mahashivratri.org/mahashivaratri-legends.html
2) Regarding curse of chandrama
Nobody prayed on behalf of chandra. chandra himself did penance for 1000 years in prabhasa kshetra as any kind of diseases cannot enter that place and pleased with chandra's devotion lord shiva made him shaap mukht
since legend of shiva ratri has been tampered i will not be surprised if other aspects are also
tampered.
However i dont intend to offend any body with this post i merely stating i know please feel free to correct me if anything's wrong
Regards
Krishna