Your Flickr stream is just all the photos you've ever added to Flickr - so yes, you can just go on uploading more (and I tend to do half a dozen at a time, because I like the very old uploadr, and that's how many it does).

Also, don't believe the dates on my Flickr stream, because I edit the photos (at the very least I reduce the size) and that seems to overwrite the date - so what Flickr tells you is when I edited (i.e. uploaded the photo).

Not sure what you're looking for re. album - tell me more?