Can I change the invoice delivery address header to read work address and set the default attachment on invoice setting to email with invoice?

It's nice to see you here today, @smelect. 

Right now, there isn't a way to change the invoice delivery address header to read the work location. As an alternative, you can update the address in the Content tab from the Custom Form Styles menu. Then, make sure the Shipping field is checked in the Display section. Please first make sure to update the Billing and Shipping Address information of your customers before performing the steps below. 

1. Go to the Settings (Gear) icon at the upper right. 
2. Select Custom Form Styles. 
3. Locate the invoice template, then click Edit from the Action column. 
4. Go to the Content tab. 
5. Choose the top part of the template. 
6. Click the Address section, then update it. 
7. In the Display section, check the Shipping box. 
8. Click Done. 

The screenshot below shows you the last three steps. For detailed instructions, go through this article: Customise Sales Forms. 

For your second question, you can check the Attach to email box when you create the invoice.

This helps you set the default attachment on invoice setting to email with the sales form. I'll walk you through the steps. 

1. Go to the Create (+) icon at the upper right. 
2. Select Invoice under Customers.
3. Enter the necessary information. 
4. Go to the Attachments field at the bottom left. 
5. Double-click the file you'd like to attach. 
6. After the file is uploaded, check the Attach to email box. 
7. Click Save and send. 

See the screenshot below to show you the last two steps. 

You can always go to the Sales menu and locate the customer. Then, check the invoice's status from the Status column. This helps you track which invoice needs to be sent or re-sent to a customer. For more details, see the How will I know if already sent an invoice? section through this article: Send An Invoice. 

I'm here anytime you have other concerns. Have a great day, @smelect.