Fiora's Rework - A Question or Two

This may have been asked elsewhere - quite frankly there are so many threads that I can't be bothered to go through them all.

So. Fiora needs to be a fencer.

This new kit has two problems (the answer may just be "high ratios").

1. What is to stop Fiora from building particularly tanky to survive for the true damage and heal. I see this as being a problem with her theme. She shouldn't be particularly tanky. That just doesn't feel right for her.

2. What is to stop Fiora from just dealing the last hit on a target for the heal - this, again, is not in line with her theme. She needs to be darting in and out of the fight constantly, not just jumping in at the end. I know this gives a meaningful decision (more damage or immediate heal) but I am not sure this should trump her theme and gameplay fantasy.