We're in the process of choosing a technology to build a site. Umbraco looks like a decent CMS and comes pretty highly recommended and reviewed. Alternately we can write a fully custom CMS using the .NET MVC framework.

There is going to be a lot of content management of structured data, much of which will need to be validated.

For example, we'll want to manage lists of stores, which will be in categories (eg., fashion, restaurants, etc.) Each store will have a large image and a thumbnail that we'd like to auto-size & crop to fit in a predetermined design/template. There will be a plain text title and rich text body copy. We'd also like to be able to provide an interface to order this list of stores arbitarily, and form input will need to be validated, often using custom validation logic. (There are many other types of data to be managed, this is just one example.)

We'd also want to be able to assign different administrative/content management permissions per account. Eg., one user will be allowed to manage news stories, another would manage the store listings but not store categories. Another user would have access to all of those.

Many (but not all) items will also need to have localized content (in up to 3 different languages.)

We'd also like to be able work with custom session variables - front-end users will be authenticated using an existing web service we'll connect to, and then some pages will display different content to these logged-in users.

Does this sort of app sound well-suited to Umbraco or would we be fighting against it to implement these sorts of features? Our main concern is to provide clearly labelled, structured and validated forms for content entry so the content managers find it easy to use and can't easily break the site layout.