you got a problem. the kubota specs says loader can lift 235lbs. I am sure It can lift almost double, but with no counterweight, you will be doing wheelies for sure. And for steering, have fun. If you cant lift it with bucket, the curl will if the relief is not set too low.
You might wanna run down to your local tractor supply store and pick up the 3 pt hitch carryall and turn the lift pins inside to make it fit on your BX. The 3 point can lift 1200lbs and at least you will be more balanced and have steering.