Change Axe's knockBack to knockDown

Well, there are two obvious solutions to your concerns. The first is to have the animation play regardless of whether the person is blocking/prompting buffs or not. The second is to not have a means of blocking/prompting buffs but instead allow a simple means of canceling a buff after it's been cast (for example in WoW you can end any buff early by right clicking on it).

I see where you're coming from with not wanting to waste long recharge buffs on people who are going to block/cancel them but in my experience those aren't the ones that cause problems, no one in their right mind would deliberately refuse fortitude or AB. However, for some buffs (particularly speed boost and the thermal shields) the dislike of the buffs by some people is not a personal opinion but a matter of practicalities. I've been on a plenty of teams where people would ask not to be speed boosted since it actively hindered their ability to play, generally because their computer was older and couldn't handle the extra speed very well. In most of those cases the buffer in question simply didn't SB them and all was well but in some cases he did buff them which invariably led to arguments. In most cases it pretty much came down to "sorry, I was trying to re-SB the 6 other people and mis-clicked" although in a few cases the kin would take an attitude of "you'll take your SB and you'll like it" which if I was the team leader would be grounds for a kick since as far as I'm concerned that amounts to griefing.

Now in both these situations having the ability to block/prompt buffs would solve the problem entirely. The buffee does not get the negative performance associated with problematic buffs and the buffer can just go ahead and buff the entire team without needing to remember which teammates do not what buffs.

EDIT: Just thinking about how I'd do it, rather than have a prompt (which I already find annoying for rezzes and mystic fortune) what I'd like is to be able to cancel an ongoing buff in two different ways. First have the ability to right click on the icon with "cancel buff" as a new option on the context menu and secondly add a cancel buff slash command. The former means that people have a way to cancel unexpected buffs during non-combat situations (i.e. costume contests) while people who want to avoid specific buffs all the time for performance reasons can setup a bind/macro to allow them to cancel them all with a single click during combat.

For example if you find that the fire shields and speed boost impact yuor performance you could do:
/bind f "cancelbuff Speed Boost$$cancelbuff Fire Shield$$cancelbuff Plasma Shield"

That way if they get cast on you you're a single button press away from no longer having them.

Catwhoorg is right -- axe has no inherent knockback powers. Carefully-monitored Axe dos not actually fling around anything at all except lower-level foes and most clockworks. I've just leveled up an Axer and been whaling away with the axe on all kinds of stuff and I can tell you he's right.

It's also right that the OP was poorly thought-out and researched.

Almost every time I see a knockback complaint that I know to be wrong ("Remove the knockback from fire/ice/whatever!" "Why does Ice Slick suddenly do knockback?" "Why did they nerf Freezing Rain?") it turns out to be a clockwork-based issue. Even when the poster is cagey about remembering (or admitting) what he was fighting, (although to be fair that was not the case in this thread) it ultimately seems to have been a Clockwork issue more often than not.

I think Clockwork should have some kind of a damned warning -- not dialogue, not a label, but maybe a complete cut-scene movie that stops play and explains that the darned things take extra knockback and PLEASE DON'T RUN TO THE FORUMS AND START A THREAD ABOUT IT. We face this complaint regularly, and usually the person who reflexively posts without researching the issue winds up angry and insults someone, which only makes the whole affair even more frustrating. Over and over we have this thread or its analogs...almost on a regular schedule...like, well, clockwork.