Phabricator: how to make arc diff ignore untracked files and how to edit reviewers

I recently set up Phabricator for my team, and I have two questions regarding to "arc" behavior.

1. When I want to send a review, I do git add git commit arc diff now, if I have untracked files, arc will not let me do it unless I commit those untracked files or delete them, is there a way to just let arc diff generate reviews for what I have commited but have not pushed.

2. When I successfully proceed with 'arc diff', it ask me to fill up "test plan", which is fine, and "reviewers"... which is troublesome in my opinion, because of two reasons: (1), I don't know what format of the person is expected, and I don't know how to spell some of the names (2) When I need 10 people to review my code, I need to write ten names. Is there a way I can leave this blank first, and then go to phabricator.mydomain.com to edit the reviews, and send the review request?

Thanks

For number 1: If you have changes in untracked files, they should be in the git ignore and arc will respect it. Otherwise, it should give you an option to append them to the commit, you should be able to select no.

For number 2: it is expecting the username for the reviewers. Also, you can put a project as the reviewer and it will message all members of the project. Simply put #Project_Name as the reviewer.