this situation sounds very dangerous to me. a Domme that would command or require a sub to not have or use a safeword does not really understand the level of trust needed to have a long-lasting, deep D/s relationship.
i don't understand how some Dom/mes get the idea that the option of a safe word somehow demonstrates their control and trust. it is just the opposite. establishing a safe word does not make the sub "hold back" from the Dom/me, but rather gives them the freedom to more fully embrace the control.
it is like the emergency brake on a vehicle. something that you can fall back on for your protection... but you hope you will never need to use it. with the proper maintenance and care of your vehicle - you probably never will. but knowing that it is there, gives you a greater sense of security and calm.
it sounds to me like she is more intent on controlling her subs and pleasing only herself in the process.... that is more like rape than a relationship. she takes, but without responsibility.
for a "one-time" fuck... the price is just too high.