Firstly, this FAQ sheet located at the top of this forum might be of assistance
http://www.ssnakess.com/forums/showt...threadid=49220
Draping around your neck is a handling no-no. A baby is fine (but don't be upset if you get nailed in the face
). I know at 4' it isn't a major threat, but still not a great idea either. These snakes are incredibly powerful, and often underestimated. Every single fatality associated with large boids and people has been a result of them improper handling them, and most if not all were by wearing them as a necklace. No such thing as a 'tame' snake, just a tolerant one. They are still instinctive animals, and all it takes is something to set off one of their highly tuned responses.
There are a lot of great cage manufacturers down in the states. Plastic caging is my personal favourite! Barrs, Boaphile, etc. would be ideal for your location. Stay away from wire on any cage, it will cause injury as well as it will not be able to hold any hea or humidity in.
4' is VERY small for either a true redtail or Colombian boa at 5 years of age. They generally do the bulk of their growing in the first 3 to 4 years.
As for water in the face, that likely will have no effect if a snake has latched on to you. Many boas will actually let you mist their faces in their enclosures when they are just sitting there. I've never used liquor, but any hard liquor would be suitable. Vinegar works quite well, just put some in their mouth and they should drop their bite.
An average, healthy adult boa should typically be fed approximately every 2 weeks for maintenance. However, it doesn't sound like you have a normal, healthy adult boa. If she is underweight or severaly stunted, you may want to feed at closer intervals. It's hard for us to say what your individual snake needs without seeing her firsthand, as well as her behaviours.
As for decorations, stay away from plants. Boas will just destroy them. Logs, large branches, platforms, hides, etc. are much more suitable