I'm finding it impossible to clean up my templates and to present right in emails. Anyone have any resources or answers to the following?

1. Scaling to display accurately/consistently across devices. For example, logo cut off on phone, border right side not showing on desktop pc.
2. Font size discrepancies. While editing, font size is consistent, but when in use, one line can be a lot larger than the next (See attachment 1_image.png)
3. Line spacing - is there a way to change the spacing between lines? Seems to space very inconsistently from one line/paragraph to another