ElizabethAnne,
You're welcome!
Tagging is very cool...I'm using it extensively in StLouie.com. There, you will see that there is a Random Tag widget on the front page. It chooses a Random Photo Tag and displays a bunch of images with that tag using the jCarousel javascript to get a slider (I just haven't had time to upload enough images to actually scroll yet :-( ). If you go into one of the posts, you'll see that there is a Related Images gallery at the bottom, this is driven off of images that are tagged with one of the tags of that post. PExtend adds the tags to both the images and to the Posts that get created. So, you can tell the related images gallery to show all images with one of the tags of the current post.
So, to answer your questions:
1) You've got that going it seems...To add tag field to your Upload form, add these parameters to your shortcode: post_tags=true post_tags_label=’Add tags:'
2) It doesn't create a separate gallery for each tag, and that really is the beauty of tags. The galleries that display them are dynamic...in other words, when a tag gallery is displayed, it pulls in any images tagged with the specified tag. So, one Tag gallery can show any tag...you just specify the tag in the gallery short code.
Here's the shortcode I use for the Related Images galleries in StLouie.com:
[photosmash create_post='image_post' tags='post_tags' tags_for_uploads='post_tags' form='related_photo' post_excerpt_field='description' layout='related_photos' post_cat_selected='post_cats']
Note that create_post only works if you have PExtend installed and configured. Note that tags='post_tags' causes the gallery to grab all images that are tagged with any of the tags of the current post. Same goes for tags_for_uploads='post_tags'...this is telling the upload for to automatically tag new images with the same tags as the current post. Note that 'post_excerpt_field' is a PExtend setting, as is post_cat_selected.
3) Cannot currently do this. In StLouie.com, I use the PhotoSmash Photo Tag Cloud widget and the tags on the posts to provide tag navigation. The photo tags are stored as alternate WP taxonomies, and I haven't built in displaying the tags in the layouts yet.
4) Only place you can do this right now is either in the PhotoSmash Photo Tag Cloud widget or by using something like my Related Images galleries where you have a shortcode something like: [photosmash tags='post_tags'] This will cause the gallery to display images of whatever tags are on the current post, so you'd have to have a post with the baseball tag displaying the gallery.
Maybe that gives you some ideas for work arounds where there are gaps in the current solution with regard to your requirements.
BB