Youtube questions

Do you need to have a gmail email address to post videos there? I do have a secondary gmail account I could use if that's the best option.

You don't technically need Gmail, just a Google account. But you can use your secondary Gmail account to upload videos to YouTube.

People who post videos have a name listed and I'm wondering if that is connected with the email the user is using to post the video, or can you make up a standalone 'screen name' for use on youtube? Does one have to set up a youtube 'account'?

You can use a different YouTube screen name. But don't need to setup a separate YouTube account. However, you can setup another Google account if desired.

After you post a video, I assume it can be modified, changed, or deleted later?

You can set your videos to be public or private. And whether the public video is viewable by everyone, available by Google or YouTube search. Or public but limited to those who have the specific URL link. I tend to use the second option for forum posts.

Modifying YouTube videos is limited. You can use their video editor. And can delete an existing video at anytime, or just make it private so not viewable by the general public.

Is there a preview option to test the video before final posting?

Yes, just mark the video as private until you have previewed it. Then you can change the video status to public.