In my early days I played with Germany bcs I loved the panzer but had no idea about his special char.

No I am finishing a game on Warlord Difficulty 1000 points ahead of my enemy, and I discovered the tank they are on rifleman. I get discoveries every 5 turns.
I have a GP farm which doubles as a high Hammer city and can produce anything in one turn. I am playing with Peter of Russia I think his char are really good.

I hate too micromanage armies and don't want to sacrifice good units so war is not my fav. but I got 3 great generals -> 2 academies 1 west point :D

Can someone explain to me how other characteristics effect the game play?
And is noble that hard?

Noble isn't that hard. It's the "fairest" level since AIs get no bonuses or penalties compared to the human player. Move on up. The AI sucks at warfare.

What bonuses do I get if I play a level easier?

Faster tech rate (compared to the AI) and maybe a bonus tech (not sure about that though). Reduced maintenance cost. Better results from tribal villages. Stuff like that.

Hmm. Well I am playing noble on large map continents with Mehmed II. I have a moderate score and im using my janisser to conquer Aztecs bcs they declared war on me...*****es.

What is cultural victory?

Cultural victory on nomal speed = 3 cities with 50000+ culture. Lots of cathedrals is the way to go normally.