Like any father, Dr. Light would want to shield Mega Man from the emotional heartbreak of knowing that his brother was dying. Though its slightly more cruel to allow him to hear it from him greatest enemy instead.
that explains the fighting
Well with protoman being a prototype of humanoid robots there are Some flaws in him. Be it a bad power core, stupidness, or a tendancy to blow up. Any one of these are good examples, for any prototype
*pokes ryan* isn't the image of protoman suppose to be the other direction (neck to the left of the screen opposed to the right) like he was laying in the last comic
It's just looking at him from the other way around.
Protoman got knocked on his back, but that doesn't mean he's down for the count does it? He can get up and continue fighting, or at least run away.