Yes, paint is part of the build process. So if a member has a paint issue and a pic makes understanding the problem clearer, then yes of course a picture should be posted. Such pictures should be posted direct to the post, NOT the gallery.
ALL pictures related to a thread should be either posted to the thread or linked from a photo host site. If the pic is linked to the gallery, I have to open up another tab. Then I will make a quick decision as to whether or not I want to see the image, and the answer is generally NO.
Requesting constructive criticism posts are gallery posts. They are simply 'look at my work' posts giving permission to give criticism.
Repeat topics; lots of members take issue at this, personally I have no issue with this at all. If you have a question and the search does not bring you an answer or you would like more opinions, then post it. If you are bored with the question, then don't answer it, move on to something that grabs your interest, that is what I do.
If you have several questions then it is usually best to start a thread for each question unless they are closely related. Members, especially new members should not have to worry about whether they will be criticized for asking a question because it may have been posted before.
DAve