Right, the deck code thing was merely a suggestion. If you feel like it's a cool thing to add to your posts, great. It's up to you.
Also the mobile GU app is still full of bugs, I'm not sure you can actually play there without bugs making you lose sometimes?
Regarding the Necroscepter, you decide to use it or not. If you want to win games and rank up, it is definitely a very strong card that can carry you many times. But if you're just playing for fun and want to try out your own strategies, etc., I think you should do what is most fun to you.