Other thing is that there is unfair and unsportsmanlike play - for example in my current game against an australian opponent named "Benjilol" - (even a premium member!) opponent refuses a draw although I keep checking him for about 15-20 moves.
That is really dumm and unsportsmanlike !
No, it isn't unsportsmanlike.
Some of it is because of internet connection. Sometimes when my connection is bad, it disconnects me, but I try to get back in immediately. I don't try to get back at those who disconnect on me or hurl insults. In the later, I disable chat with them. I block both the disconnecters and insulters. I think sometimes people do give up too easily. I played someone who disconnected after he blundered his knight. Yeah I was up a knight, but there were complications and I would have played on in his position. And the person was rated > 2000 who did this. I thought of sending a message to this effect to him, but it seems with the people who do the disconnecting or insulting that this would be lost on them, so I don't bother.
If you can't repeat moves or checkmate your opponent then your opponent has every reason to try to A: escape, B: Look for counterattacks / -checks. Nothing unsportsmanlike about it. From that game I can see checking is the only thing u got going for you so I understand your opponent, as soon as you don't check he gets time for the counter attack.
If you want the draw just try to repeat moves, then you can claim it anyway.
I actually find it very annoying when people offer draws when there are lots of pieces/pawns still on the board. I hope you only offered one draw and not with every move.