I would like to know if I can use a developer key to publish an app for free with Ads, of course attributing TMDb as the source of whatever date and / or images you use (my app simply provide information about movies). Is it right, or I can use a developer key only for an app for free without Ads?

I've read before that use of ads is fine for the free API Key!

I don't know about the other point though

Thanks Marr for your answer.

Anyone could help me for my second point? If nobody can help me, I think I'll try to make a new request for a new developer API with a new application name..

Gotta wait for @Travis to see this :)

Ok. Thanks

Another doubt is: if I want to change the name of my application (I mean a different name from the one that I provided when I requested the developer key), I need to make a request for a new developer key, or I can use the same developer key used until now?

You can use the same key. Just make sure to update the name in your account preferences if you change it.

Ok, of course! Thanks!