[mvdan]

You might be getting confused. gofmt does not warn about lacking comments, that was golint, which has since been deprecated.

gofmt does not divide or re-join imports into groups, but gofumpt does :)

Neither gofmt nor gofumpt enforce a character limit on lines. Some form of line length limit is the most common gofumpt feature request by far, but one that I haven't been brave enough to release in any form.

Perhaps read gofumpt's README, it has a lot more information.