Membership headache

1. Write some code to automatically create a page for the users when you create them (the users). Save the page id in the user-meta.

function create_new_user_budget_page($user_id){
        if (!$user_id>0)
                return;
        
		//Get user info
        $curr_user = get_user_by('ID',$user_id);
		
		$title = $curr_user->first_name . ' ' . $curr_user->last_name;
		if($title == '')
			$title = $curr_user->nicename;
		
		// Create post object
		$post_args = array(
             'post_title' 	=> sanitize_title($title),
             'post_type'	=> 'page',
             'post_status' 	=> 'pending',
             'post_author' 	=> $user_id
        );

        // Insert the post into the database
        $user_table_page = wp_insert_post( $post_args );     
        //Store the page ID in the user meta 
        update_user_meta($user_id,'_table_page_id',$user_table_page);
}
add_action('user_register','create_new_user_budget_page');

2. Use wp_reriect_url action to redirect the users to automatically redirect the users to the page created for them, wheneever they login.

function user_login_redirect( $redirect_to, $request, $user ) {
	//is there a user to check?
	if ( isset( $user->roles ) && is_array( $user->roles ) ) {
		//check for admins
		if ( in_array( 'administrator', $user->roles ) ) {
			// redirect them to the default place
			return $redirect_to;
		} else {
			 $user_page = get_user_meta(get_current_user_id(),'_table_page_id',true); //retrieve the page created earlier
			 $user_page_url = get_edit_post_link($user_page);
			return $user_page_url;
		}
	} else {
		return $redirect_to;
	}
}
add_filter( 'login_redirect', 'user_login_redirect', 10, 3 );

3. WordPress automatically takes care of auto-saving the posts every few seconds, upon editing.

You need to add the code which I gave in the functions.php of your theme file. Or perhaps create it as a plugin.
If you want to create it as a plugin, then follow these steps:
1. Create a directory and give it a suitable name. For eg claudesmusicbox or claudes-music-box or whatever, just ensure that the directory name does not contain any spaces.
2. Inside the directory create a file and rename it to whetever-you-like.php
Again ensure that it does not contain any spaces.
3. Now open the file in a text editor (like Notepad++) and enter the following code:

<?php
/*
Plugin Name: Claudes Membership Plugin
Plugin URI:  http://www.claudesmusicbox.com
Description: Plugin to do some magic on CLaude's website
Author: Claude
Version: 1.0.0
Author URI:  http://www.claudesmusicbox.com
*/
?>
<?php
function create_new_user_budget_page($user_id){
        if (!$user_id>0)
                return;
        
		//Get user info
        $curr_user = get_user_by('ID',$user_id);
		
		$title = $curr_user->first_name . ' ' . $curr_user->last_name;
		if($title == '')
			$title = $curr_user->nicename;
		
		// Create post object
		$post_args = array(
             'post_title' 	=> sanitize_title($title),
             'post_type'	=> 'page',
             'post_status' 	=> 'pending',
             'post_author' 	=> $user_id
        );

        // Insert the post into the database
        $user_table_page = wp_insert_post( $post_args );     
        //Store the page ID in the user meta 
        update_user_meta($user_id,'_table_page_id',$user_table_page);
}
add_action('user_register','create_new_user_budget_page');

function user_login_redirect( $redirect_to, $request, $user ) {
	//is there a user to check?
	if ( isset( $user->roles ) && is_array( $user->roles ) ) {
		//check for admins
		if ( in_array( 'administrator', $user->roles ) ) {
			// redirect them to the default place
			return $redirect_to;
		} else {
			 $user_page = get_user_meta(get_current_user_id(),'_table_page_id',true); //retrieve the page created earlier
			 $user_page_url = get_edit_post_link($user_page);
			return $user_page_url;
		}
	} else {
		return $redirect_to;
	}
}
add_filter( 'login_redirect', 'user_login_redirect', 10, 3 );

?>

IMPORTANT: There should be no whitespace (or line break) before the opening <?php or the closing ?> tags

Now to answer your other questions:

2. I create a separate page for each member, with the title of their page being their username eg ‘claudesmusicbox”.

The function create_new_user_budget_page in the code above does exactly that. It creates a page with the user’s name. For eg. for a user with the name John Doe, the page would http://www.claudesmusicbox.com/john-doe (i.e FirstName-LastName)

If you want the page name to be http://www.claudesmusicbox.com/johndoe2017 (i.e username), then you need to change the lines :

		$title = $curr_user->first_name . ' ' . $curr_user->last_name;
		if($title == '')
			$title = $curr_user->nicename;

to
$title = $curr_user->user_login;

This will create a page automatically when you create a user. You can also optionally set a password for that by password-protecting the page.

It is important to note, password-protecting a page will prevent unauthorized access only on the frontend, not on the backend.
Depending on the user role (i.e. contributor, editor, author, admin etc) users may (for roles admin and editor) or may not (for roles contributor, author) be able to see other user’s page.
So if you want users to not be able to see other user’s page in the backend, them assign them the role of either contributor or author.

1. When members log in, they all land on a “Members List” page that all Members can see, that has each member listed alphabetically via their username.

The function user_login_redirect will take care of that. It wil redirect the users (upn login) to their page only.

So you see that the redirecting and creating pages is already taken care of by the code above.

But what I am really interested in knowing is how do you embed the spreadsheet in the page?

Now I just have to figure out the spreadsheet part of it. I’ll let you know.

1. If you want an actual spreadsheet, then you will probably need o use on of the plugins that enable embedding google docs into WordPress page.
But it would require providing Google API keys.
So if you need to go this way, then it is better to create a separate google account just for this.

2. On the other hand, if you just want to give the users a spreadsheet like look, then probably you could go with a plugin like TablePress that has the ability to export its contents to xls or csv