You're welcome, DesiLinguist. Yes, I used the default iLiad PDF viewer and you have all available options: annotation, page flips, zoom, pan.
I wrote the comment on the 3rd screenshot with the default stylus. You can change the shade and thickness of the lines drawn by the stylus. You can erase annotations with the stylus, too.
I loaded up the browser on my iLiad (Midori) and took a look at the website you linked to above,
http://aclweb.org. I could navigate around the site, but not browse the pages you linked to. Web browsing isn't great with the iLiad, it can be slow and buggy, but some sites are OK. e.g. Its easy to do a google search and I can send/receive emails via Fastmail (webmail) on my iLiad.