Wow, welcome to the wonderful world of Nanoha! Anyways, onto answers:

1) It probably depends on the kind of attack. Starlight breaker is probably fine, but Fate's giant Zanber attack that she uses to destroy the BoD's shields, which is essentially an enormous laser sword, probably could not.

2) Again, it depends on the Magical Girl. In the first season of Nanoha, the transformation takes a few seconds, and can be interrupted, but there's a strong barrier spell around her to protect. I have no idea how it works for Sailors, but go with Rule of Funny.

1) is certainly possible. Hopwerever, the poeral should be actually bigger than the width of the beam, otherwise crazy stuff might happen.

2) depends on the series. For example, Nanoha has transformation sequences, but they are instantaneous to the outside viewer. Same thing for Madoka Magica. I don't know in Sailor Moon, though.

1) Provided your agents react fast enough, they can play "Portal" with thermal discouragement beams lasers. It would also provide a good opportunity to impale a Sue on her own sword.

2) The comedic effect here is just too good to miss.