Regarding the posts, we are not able to change the website structure to make all posts within 2-3 lines due the different languages’ usage (Chinese-English).
We can handle it if you’re using only 1 language.
But in this case you can handle it manually by editing your posts, click on screen option and check on “Excerpt”.
Once you check “excerpt”, you will find a new text box at the posts’ page to add the text you want to show manually.
If there is anything else you need, please let me know