Typographic alignment questions

Sam,

In this case with general left alignment, it would make sense to have the heading left aligned.

You may (or ought to be able to) expect the detailed alignment to correspond to what is inbuilt in the font when used with left alignment (or justification) in applications such as Illustrator, InDesign, and hopefully word processors.

You may use that as a reference.

Basically, in a case like the one shown, the pointed/narrow left side shapes such as the S, t, and f, will extend (a little/tiny bit) further left than the rounded shapes such as the C and the u, to give the appearance of left alignment (the appearance of everything starting at one and the same vertical line).

Appearance being the key word, you may say that what looks right is right (if you look in the right way).

This may be sufficiently woolly.