The Bloodknife which Gawyn encountered first was probably just scouting the area and not about to make an assassination attempt. It makes no sense to attack the Amyrlin on his own when there were three others Bloodknives still alive at that time. They probably knew about the possibility of wards too.

I'd say the main reason Egwene came close to being killed was that whole plan with the wards and using herself as bait had a huge glaring hole. She should've simply secretly Traveled to a safe location every night (one of the hundreds empty apartments in the Tower, for example) and not risk herself, and then Travel back to her rooms if the wards were activated. But why use common sense when you can rely on a plot armor and luck to save you?