@user2332873 - I think I have a good news for you!
Refer this link which was very helpful for me in a similar task as yours - Creating a news blog using SXA. You will be having step by step instructions on its implementation with extra features like buckets,tag cloud, tag list, load more, pagination etc.., that might be you of great use to your task!
For you first requirement,
1) Title of Hero Image needs to come from body of another the news article page and need to pick first 10-15 words
Yur solution can be - as mentioned in this blog, where you can have two fields 1)Introduction (this field will have the first 10-15 words) and 2) Content (this field will have the whole content beginning from the first 10-15 words in Introduction field) and use rendering variants pointing to these fields
I think you have answer as for your second requirement from Richard Seal