What (pages) do I look at, how much can I really find out?

Under the player's profile image (or name if they have none) are a series of buttons that contain papers which they can add various information to, as well as their inventory and public logs, which contain messages left on them by other players.

Now, the following advice comes from a master voyeur...I mean, information gathering master!...so pay attention. 

If you never talked to a player because you are a) shy b)full of hatred towards said player c) in front of their dead grave/profile, then it's not too late to not do it. You can gather tons of information from various pages and then decide how to best use them. Personally, I suggest talking to everyone and trusting no-one. Be that social fellow who talks in great detail about the party, only to bail out at the very end since the bill for the beer is on him!

First and foremost, check out their trace they leave in chat. Click on their name and see details. Plenty details there, like land affinity, active days, alliance etc and most importantly - NAME. Lots of information can be gathered from the name - if the player is called EvilShinchan06, well...they might be evil.

Next up, log panel. People leave comments there and based on those comments you can learn about the player. Once again, don't trust anything, just collect data. Under the avatar, if they have it, or just under their name, there are a few buttons. Some of them open the player's papers, which - shocking! - are public and some people write in great detail about themselves and their beliefs. 

But that may be much too little, at which point you may want to open up their profile page, which can be done by opening yours, clicking on that link and replacing the name with theirs. You know there's a player called BigC, but you've only seen him twice in your life? Open their profile! Profiles are great, you can get a glimpse of their creatures as well.

Up the level and prepare your acousticremains spellstone, if you are a freak. Personally, I don't recommend using those except for roleplay or quests purposes, but there's also nothing inherently wrong with using your spellstones as you see fit. Probably. Or open the forum and check out their forum profile, their posts and mood panel posts.

Bottom line is, if you need to gather data about a player without interacting with the said player, there are ways to do it. People leave traces, even if their miserable lives are like specks of dust in the wind. How you use that information is up to you - you're not a freak and you're interested in playing the game, you'll do fine; you're a bit on the dark side, Luke, I'm your father, well...see you in jail!