You won't get penalized for playing against a bad opponent, but if you're playing against someone whose renown for their ingame skill then yes it will be taken into account Bruci.
As for the loss of a limb, it will affect the replay, but that'll be included in the general atmosphere of the replay.
Basically if you get dm'd and it makes the replay look bad then yes, it will affect it, but if it still looks good then it won't as much.