Displaying a list of image thumbnails, with click-through
Creating a new Image content type is a good way to approach this.  Views can certainly display the content as a list or a gallery-- or some combination of both-- but you may want to think about how you want to display the content in the gallery.

Comments are handled by Drupal out-of-the-box so I don't think you have much to worry about with regard to them.

You do not need to use the Insert module if you're just going to be uploading an image file.  If you're only going to be adding 150 images once, I would just create the image nodes one-by-one.  If you anticipate having to add lots of images regularly, you should post a separate question asking for a solution to that.

Here are some resources to get you started.

First, there's a screencast about building a gallery in Views.  Although this is for Drupal 6, and a fair number of things have changed in Drupal 7, the basic principles are the same.

Second, there are some helper modules which can give you pop-up and gallery-type effects without much work.  Two of the more popular, well-supported ones are:


Lightbox2
Colorbox


Either can be used on its own or with Views.