I personally do not recommend tumblr as an image storage site, because it isn't an image storage site. It's for posting and sharing content, whether it be images or art or people's random blog stuff, or anything. A tumblr is like a blog, so it's more of a site for communication than simple storage.
I use photobucket and have no problem posting my images. I don't know why you get a link under your photos. When you go to the image you want to post, do you copy the code that says "DIRECT" or "IMG?" The img code will indeed give you a link back to the image on photobucket, but the direct code will not, and you can use the [ img ] buttons on CS yourself to make it show up on the forums.
As for making links out of words, this is the template:
- Code: Select all
[url= link here] words here[/url]
The link can be to a page or an image or whatever, and it'll show up as words.