What should you keep in mind ? I need a little bit more information. Is it that you want to use the plugin with your theme or that you want to load the custom fields through your theme.
It's a bit too open ended so i need some specific details.
Actually there isn't much I can say about the compatibility since our plugins are generally compatibility with most themes.
If you're building your own theme so long as you're using standard practices for creating the template files then views should work flawlessly. If you use a custom function to load your content then views is able to identify that function.
For the custom fields once created in Types then you can call them directly in your page template or you can use our views content templates to customise the output of your page content.
