Hi there, @erick.futuretale.

Let me share a possible scenario and help you remove the slide control on the right-hand side of the transaction.

Are you referring to the Add to Invoice slide from the right-hand side of the transaction? If so, we don't have an option to remove the slide. This slide will always show if you have transactions that can be converted to an invoice, like estimates and billable expenses.

On the other hand, you can change the width of the columns by customizing the form style. Let me guide you how.

1. Click the Gear icon.
2. Select Custom Form Styles.
3. Choose the template, then click Edit under Action column. If you haven't created a template yet, you can click the New style drop-down.
4. On the page, go to the Content tab.
5. Click the Table section or the middle part of the template.
6. Select the Edit Labels and Widths.
7. Customize the width you want to show on the template.
8. Click Done once finish. 

Here's an article you can read on for your reference: Customise Sales Forms.

In case you want to send an invoice to your customers, you can check out this article for your future reference: Send an Invoice.

Feel free to leave a comment below if you're referring something else or if you have any other questions. I wish you continued success with your business.