1. User chooses someone from a dropdown list 2. When the form is submitted the person selected from the dropdown receives an email with the form response.
This is fairly simple to accomplish using the formula and alias system: http://app.formassembly.com/pages/support/formulas
Go to your form, and create your dropdown list. Go to the advanced panel for the dropdown list, give the field a variable name like "EmailRcp", and enter the corresponding email address for each user in the list.
Create a hidden field, named something like "Recipient", and set it to be a calculated field (in the advanced tab) with it's formula being simply: EmailRcp
Now save your form, exit the form builder, and go to your notification's page. In the recipient field for the notification, place the following code: @IF(%%tfa_Recipient%%,%%tfa_Recipient%%,'default@mydomain.com')
where %%tfa_Recipient%% is alias for the hidden field, as described in http://app.formassembly.com/pages/support/formulas and 'default...' is the default email address to use if something goes wrong with the alias.
Looks like you have it all setup right. Are you a pro user? As detailed at the end of the formula page, the use of formulas and aliases are only available to pro users.