The reason you're not getting any replies in your other thread is because nobody has permissions to reply to it for some reason. I tried to post a reply but it told me I didn't have permissions.
To answer your questions, posting multiple photos in a post can be done from any device, it doesn't need to be a computer specifically.
Hyperlinks get parsed automatically by the site when submitting your post. For example, if I type
http://www.google.ca, I don't need to add the anchor tags to this, I just type the URL and it should appear as a clickable hyperlink.
In order to post multiple photos you can either upload them all under your account here and then include them in your post, or you can upload them to another server and link to them from here. I like to user another server, that way they show up as large photos in the post body rather than small thumbnails under your post.