Yes, indeed Steemit is complex at the beginning, that's why we aim at making it simpler for the beginner.
1- Thanks for the idea, it could be a good thing to explain it to the newbies. I will add it to the question list for the faq we will set up on the website.
2- Yes, absolutely. We use Steemit's wallet for Share2Steem ( as any dApp based on Steem).
3- Theorically, you can post once every 5 minutes, within the limits allowed by your Resource Credits. But I recommend you post no more than 5 posts a day, else your followers may think you're a spammer and mute you, or unfollow you. For the social networks interactions, they are not reported on Steemit. A Youtube comment stays on Youtube, so does likes etc.

About delegation, I recommend you don't delegate before you get at least 20 SP (didn't check how many you have), so you keep a minimum interaction capacity on the blockchain.

But if you want to learn more about how Steemit works in depth, you should take a look at @steemonboarding