hi,
you are right,
if you don't need to customize, you don't need a developer license (or application builder or solution builder)
you need only NAV-CRM connector license to install, setup&configure & run component.
...
from Dynamics Partnersource
look at this page:
mbs.microsoft.com/.../General.aspx requirements
System Requirements
1. Microsoft Dynamics NAV 2009 R2 with KB 2597312 applied.
2. Microsoft Dynamics NAV 2009 R2 with KB 2721512 applied.
3. Microsoft Dynamics NAV 2013.
4. Microsoft Dynamics CRM 4.0 with minimum of Update Rollup 5 or Microsoft Dynamics CRM 2011 or Microsoft Dynamics CRM 2013 must be installed or a subscription to Microsoft Dynamics CRM Online or a Partner hosted deployment must be active.
5. Note: To ensure proper integration, Microsoft Dynamics CRM and Microsoft Dynamics NAV must use the same Application locale (with the same base language, base currency, and other base field values).
6. Note: To ensure proper integration, if using Microsoft Dynamics CRM online or Microsoft Dynamics CRM 2011 on-premises with UR 12 applied, you must use the classic forms within Dynamics CRM for Account, Contact, and Sales Order entities.
..
Integrating Microsoft Dynamics NAV with Microsoft Dynamics CRM
msdn.microsoft.com/.../gg502460(v=nav.70).aspx
Walkthrough: Setting Up Microsoft Dynamics NAV and Microsoft Dynamics CRM to Use Connector
msdn.microsoft.com/.../gg481835(v=nav.70).aspx
HOW TO: Obtain a license key for the NAV / CRM Connector
www.dynamics-community.at/.../HOW-TO-Obtain-a-license-key-for-the-NAV-CRM-Connector.aspx
Good doc here (technology)
www.archerpoint.com/.../ms-dynamics-crm-connector-features-and-functions.pdf
MS Connector dedicated blog (many issues here)
blogs.msdn.com/.../dynamicsconnector
The difference between Application Builder & Solution Developer Licenses
dynamicsuser.net/.../150076.aspx
Application Builder:
You use this granule to change the business rules and special calculations that work behind the scenes. These business rules and special calculations are defined in a language we call C/AL (C/SIDE Application Language). While Application Builder includes access to C/AL, it does not allow access to existing C/AL code that updates write-protected tables (postings for instance). Application Builder lets you create entirely new areas of functionality for your application, enabling you to tailor Microsoft Dynamics NAV to fit your entire organization. This tool also enables you to create 100 Codeunit objects (numbered from 50,000 to 50,099). The Application Builder granule enables you to take advantage of the functionality included for developers in the Navigation Pane Designer. This means, for example, that you can create new menu items.
Solution Builder:
You use this granule for the same purposes as the Application Builder granule, but it also gives you access to code that updates write-protected tables. This granule gives you the access necessary to change or create any object type, and gives you access to the Merge Tool and Upgrade Tool. This granule also enables you to use the menu options Translate/Export and Translate/Import in the Object Designer. These options are not available with the Application Builder granule.