Congradulations on your blood,
I know the feeling of having a new snake that will not eat and then it finally eats.
Whether or not to move him from the rubbermaid totaly depends on your setup and the temperatures of your room. Rubbermaids work well if you keep a steady room temperature around 78 to 80 + or - a few degrees. Then you just use your heat pad to give them a basking spot of 86-90 degrees. If you keep your room colder say 72 then you will need to use an aquarium or custom cage with a heat lamp and thermostat to get the temps up in the cage.
As far as whether to move him or not that depends on the snake, I feed a lot of mine in rubbermaids and then put them back in there cages with no problems unless the snake is prone to regurging its meal.
In answer to the humidity problem, I like to use newspaper in my cages so with high humidity snakes I place a rubbermaid tub with the lid on it of an apropriate size for the snake and cut an appropriate size hole in the container and then fill it halfway with cypress mulch that is moist. This creates a humidity chamber for them and they can come and go out of it as they please.
A bad year with reptiles is better than a good year without em.