Is there any? I have no idea what the Score, Choked, and Snubbed columns mean.
That's really my main question every thing else in the program if self explanatory. :)

There is no documentation at the moment, but it's in the works.
I'll try to explain these terms fast:

- choked:
When a client is interested in a piece another client has, there should be some way to tell the other client that it will not supply with the requested piece.
Bittorrent has designed this "i will refuse your request for now, but come back later" message for this. With this message a client can also locally try to upload only to the amount peers configured in settings, with the advantage that it actually can supply each peer with a somewhat stable XX KB/s download speed.
There is also a gameplay in the choking requests involved called optimistic unchoke. This is designed to continuesly refresh the list a client is uploading to and trying to give new peers/blood a change to prove themself.

So in short choked and optimistic unchoke is very important. It tries to upload only to "the better peers" in a swarm, so it can maximize the throughput and keep things as fair as possible. It really is a smart system.

- snubbed:
Is AFAIK a pre-choke, and should be a way to tell another client for a very short time "i don't trust you and i do not upload until i see improvement".
In practice some clients do not use it fair and use it constantly to not get in the choking queue of the other client while trying to keep a connection. Bitcomet for example thinks this flag should always be turned on.

- score:
I think this a way to tell uploaded/download to a particular peer.

Hope this helps.

Well snubbed just means that we haven't received any data from a client in the last minute.

The score is something we calculate to decide which peers get unchoked (so the peers we upload to). It's intended to favour peers who give us good download speed, it rewards good sharers, and punishes bad sharers.

Thanks

sorry, to warm this up, but when someone has a score of -50, or even -10 should i bother to "ban" them manually, and what exactly does ban do? is it even fair to consider someone with a score of -50 to be a bad seeder? does this reflect, how much a peer downloads/uploads on this particular tracker, or only in what relation the peer stands with you?

No, no don't ban those peers. Score is used for choking algorithm and it depends on peer stats. Having low score does not mean it's a bad seeder or anything. Peers with low score have less chance of getting your upload slot than the ones with higher score. Specifically, score of -50 most of the time means that peer is not interested for the chunk you have and does not want to download from you - so you don't want to give him upload slot. This, however, does not mean he will not give you good download rates

does this reflect, how much a peer downloads/uploads on this particular tracker, or only in what relation the peer stands with you?

Only in what relation the peer stands with you.


Hope this clears some things.

how do i unban someone?

With versions <=2.0.3 you can't do it. Current SVN has this option and it will be included in the following v2.1

However, manually banned peers are per session only so you'll only have to restart KT and they won't be banned anymore.