Sounds like an excellent idea to me! Also, don't know if you're aware but Non-Trivial has an online course that sounds similar to what you're talking about, and Kurzgesagt has produced a bunch of videos. Good luck and feel free to send me a DM if you ever want to bounce ideas around. 

My answers to your questions:

1. You simply tell them 'you can do far more to help others than you realise by simply changing which charities you donate to'. It isn't very cost-effective in the short term but, in the long term, it helps you build a broad base of support and change cultural norms. It also disproves the harmful narrative about EA just being an elite club for tax-dodging techno-utopian billionaires.
2. Hard to say how much. More people knowing more about the biggest issues in the world seems like it would be a very good thing. 
3.  I don't think there's much risk in communicating good ideas well. Seems far less risky than communicating good ideas poorly. Obviously you've still got to be careful around info hazards, but that's doable.
   
    

I think something like that could be great! I also wish learning about EA wouldn't be that difficult or time consuming. About your questions:

1. For the people who don't want to change careers because of EA, I think you can still share with them a list of ways they still can have a positive impact in the world, something like what PauseAI has. That shouldn't have a big cost and it would possible to expand about it later.
2. Adding to what you wrote, other ways they can still have an impact are:
   1. Changing their habits of consumption, like becoming vegan and reducing their pollution
   2. Participating in the community, like in the forums or volunteering
   3. Sharing the ideas and content, like the video/ course itself
   4. Small everyday actions caused by learning more about EA, like expanding the moral circle, the causes and having a more rationalist mindset
   5. Stop working or investing on risky things, like AI capabilities
3. I don't think so.