don't need word boundary here

The word boundary in this regex is unnecessary and causes problems
when tokenizing identifiers containing `.` and `_`; for example:

- `.` is not consider an identifier,
- `.rs.` is considered as two tokens (identifier + `.` text)

Removing the word boundary should be a safe fix.
clean 'dontInsertParens_' logic; more guessing on when parens inappropriate; let console see its editor