[quote=@Emma][b]Second Question[/b]
Why are some of the threads in off-topic unusable when they are not locked, and were posted on a few months ago? For instance [url]Post Your Pikcha[/url] thread. I am unable to post anything in it.[/quote]

Threads (excluding RP threads and a few other places) autolock after some time has passed without anyone posting. You'll have to ask a mod to unlock it.