I completely agree, the photo gallery is very hard to use. Its part of the community server open source system we use here, and, as such, we are sort of stuck with what they have implemented. We are looking for a better photo gallery add on, and hope to find that soon, as I am sure other people have ran into the weaknesses you refer to. You can attach the following image file types in the forums:
jpg; gif; bmp; pcx; png; pic
You should see an Attachment field and a Browse button at the bottom of the posting window, where you can upload your file, and not have to use the Photo Gallery.
Thank you for your feedback, its appreciated.
As soon as I get a better gallery I will send out an alert email.