How do I make long paragraphs follow the source indents in TeXShop? This what I usually get:
How do I make succeeding lines follow the indent of the first line? This is so that it would be easier to navigate the source.
Currently, there is no way to make TeXShop indent long lines as you want. If you would like this feature to be implemented, you can “vote” for this feature request.
However you might want to consider breaking the long lines into shorter ones and manually indenting as you will. Some of the advantages of doing so are:
You get to indent however you want. For example, for itemizes I tend to write
\item Lorem ipsum ...
dapibus ac, ...
ornare nisi, ...
which doesn't correspond to any if the common automatic wrapping/indenting schemes implemented in text editors.
The indentation is stored in the file, so that yourself and your coauthors can “see” it regardless of the editor you use.
Tools for diffs, file merges and version control benefit from shorter lines (which in turn benefit you!).
I don't use TeXShop so I can't say for sure, but your problem might lie in the fact that your items are all on one gigantically long line. Consider splitting those up into individual lines that'll fit the width of your screen.
I know I've already answered this question and you've already accepted an answer, but Notepad++ has implemented this feature in their latest version.