That shouldn't really hinder your agility.
It could actually make you more agile depending on your current physical condition. For example if your obese then trimming the fat and replacing it with muscle will increase your agility.
I lift weights religiously and to a little bit of boxing when I have some free time and I've noticed that I'm a lot quicker than guys much smaller than me, but I do tier out a lot quicker.
Buff definition: Having good muscle tone; physically fit and trim.
So yes, but anything more will slow you down. Parkour should actually do this for you.
yes
train like gymnasts and olympic weightlifters
you may draw your own conclusions.
I want to get buff Im not talking Arnold , more like gerard in 300 but i want still want to be agile enough to do parkour and martial arts and excel at these things is it possible if im buff?