Image Management gives me headache

I am trying to figure out the best approach for image management in a site I am working on. I have now spent hours reading about various modules, searching here and on google etc. My head is spinning now, and as a "last resort" I post here in hope that someone can point me in the right direction.

What I want to accomplish is:

Custom Content Types:
When I create a new node I want to both be able to have inline images in the text area and use imagefield (or similar) for single images. I also want to be able to have a set of images that can be viewed in a lightbox2 slideshow. The slideshow should both be available through a link and be possible to combine with the single image when clicking on it to view it in lightbox.

Adding/Uploading and additional information
I want to either be able to add an already uploaded image using an image browser or upload a new images. When uploading I want to be able to add information about them, such as caption, copyright, author, etc. I also want to be able to relate the images to various taxonomy terms such as a product name. I want some of this information to be automatically used either on the node pages or in the lightbox view. The closest match I have found for this is Image Assist so far. However imagefield is not compatible with the image module...

Different sizes
These images will be shown as thumbnails, previews and full views mainly unscaled using lightbox when clicking on them on the content page.

Manipulation
There is also a need to be able to watermark images, either by using, for example, the site logo and/or the copyright holder for individual images. Imagecache Actions has these features, and more, but then again I believe I will run into the same incompatibility problems with the image module as above.

Reusing
Images will also be reused on more than one page. When doing so I optionally wand to be able to enable a link back to the main node the image belongs to or be able to use that in related links.

Views
I also want to be able to access all images from views so I can create various views, including blocks, I need on the pages. This includes access to the additional information added with, for example, Image Assist as well as node references.

I want to be able to create blocks that has an automatic slideshow where images is changed ever x second. These images should be linked to a content node based on a relation set for the image.

ConTemplates
This is probably the easiest part as I will be working with the content type that thus should have all needed information available.

Galleries
At this stage galleries is not really important, but it is something that most likely will be used in the future.

What node is using the image
When browsing images I also want to be able to see which nodes that is using it. Both the main node and then all secondary nodes.

As said in the beginning I have gone through more or less everything I can find about this topic, but not found a suitable solution. I have found most of the features I need, but then I discovered that the modules needed doesn't work properly toghether, such as image module and imagefield.

I simply want to find one solution for this, not be forced to use different solutions where images are managed differently and I can't get a complete overview of all images on the site.

I have also looked at the Assets module, which seems very promising, but it is not ready for Drupal 6 and not much seems to happen with it.

I hope someone here will be able to guide me through this so I can find a solution that will best match my needs and that will be manageable as the content on this site grows.