A. If the video has a specific place that it should sit (and they can't move it around) then we can create a separate editable section which is only for the video, so they would paste their embed code into it, rather trying to place it inside the html of the other content (making it less confusing as they won't need to worry about where inside the html they should paste the code). Also, there is an icon in the editor for pasting a youtube url.
A. Default Primary Page
To specify the default primary page add a hidden input with the name of
capturepage. For example:
<input type="hidden" name="capturepage" value="
FILENAME.php">
Default Content Group
There is no way to do this through html. However, you can control what the default content group is when editing membership from /admin/memberships
Alternative: Use PHP
If this does not work for what you are trying to do (exa: You need it specific for a promotion, not a membership), the other way to do it would be to use php code and putting a hook for do-join.php page.
The best hook to use is a special one in the middle of the file.
To do it create a file called
do-join-midhook.php and put the php code for editing the default content group in that file. There is an object for the member called
$member that can be used with the method
setPrimaryCGroup(#) for the primary content group.
A. You can create optin forms using HTML form creator.
You can add custom fields and copy/paste the code to your 3rd party website.