Basically i mean, just like someone blocking regular users, by choosing to block "Anonymous" user then all users who post under the name "anonymous" won't be able to respond to your questions/opinions.
Seems kind of pointless. Plus, there's already a feature to prevent anonymous responses on your questions... not sure what more you could want, really. Being anonymous doesn't prevent people from leaving helpful and insightful feedback.
Yeah I would so do that. I never allow them to even comment on my posts, unless I feel there should be a good reason to not ID yourself, like in abuse or molestation cases. I usually don't post up too much on that stuff because it's almost too sad to read.