Ron.
Of course angling is a form of hunting, no one in their right mind could say otherwise. But, at least as far as course fishing is concerned, the object is very different to hunting with dogs or guns.
As to the definition af a blood sport, surely the true blood sport is one that intentionally sets out with its primary objective being to kill a wild creature for pleasure.
You cannot say simply that because a sport involves animals and sometimes blood, it is a blood sport. Take horse racing for instance. Almost every day horses are injured and some sadly have to be put down, but no one even remotely associates this with being a blood sport. ( I know there have been moves to ban the Grand National). Admittedly there is a distinction in that horse racing does not involve hunting, but nevertheless it involves animals and sometimes blood.
Even game fishing, where as you say it is compulsory on some waters to kill your catch, and blood is involved, is distinct in that the dead quarry is then taken for the table. In my opinion this differs from fox hunting in that it is 'the speakable in pursuit of the edible'.
On a social level the other massive distinction is that by and large fishing is a working class sport( Yes, I know about the Windsors and their ilk), whereas hunting with guns or dogs is predominantly the domain of the so called upper classes, despite the token novelty lottery winner ex milkman in a red coat. ( 'Our sport is open to all'. B......t!) In a way this makes us more vulnerable as we, the prols, do not have the clout of the landed gentry.
You're right to say we have to choose our words carefully. For that very reason we must be careful that the anti's cannot misconstrue our well intentioned opinions.