I have some steps that might help you with your concerns, Deano2.

We can run an individual profitability report for each project by following these steps:

1. On the left panel, click Projects.
2. Click the project name, and select the Project Reports tab.
3. Click the View link in line with Project profitability (without time costs).
4. Select the Report period, and click Run report.

You can also customise the report to include other projects or run a separate report called Profit and Loss by Customers. This report allows you to view income, expenses, and net income (profit or loss) to all customers or projects.

With regard to the custom fields, you can add the option by following these steps:

1. Click the Gear icon located in the upper right-hand corner.
2. Under Your Company, click Account and Settings.
3. Click Sales on the left menu, and select the Sales form content to expand.
4. Enter the custom field name and click Save and then Done.

The option will appear in customer transactions like invoice or sales receipt. You can also run a Transaction List by Customer report and customise it to add the custom field as a column.

For the bill, you can make it billable to a project. Just make sure to enable the billable feature in the settings.

Here are the steps:

1. Click the Gear icon located in the upper right-hand corner.
2. Under Your Company, click Account and Settings.
3. On the left menu, click Expenses.
4. Put a check mark on the Make expenses and items billable box.
5. Click Save and then Done.

When you create a bill, put a check mark on the Billable box and select the project from the Customer/Project column.

Here's a screenshot of what it looks like:

If you need anything else, I'm here to help you some more. Thanks.