I've never heard of an "agility handler". but i'm not THAT into the ins and outs of agility.
In your shoes i'd ask a trainer about options, if you can bring her to a class maybe the trainer would be able to work with her or work with you on some options for you to work with her when possible. You'd be paying for the class and bring her out but the trainer would "work her".
OR maybe if you know a teenager that would like to learn to train a dog (or maybe ask the trainer if they know someone).
Note that when you get into agility it's not a lot of running around per say you spend tons of time learning basics. I mention this as you say "blow off some steam" - it's not an intense run run run sorta activity It's more mental exercise and some physical (then becomes MORE and MORE physical as the dog learns commands/obstacles and can link them together).