Re: Switching prey items?
I don't think there's any physical danger in the choice. The snake knows a live animal when it sees/smells/senses it and will do what snakes do. That being said, the downside to switching back and forth between the two types of feeding is that bp's tend to develop "favorites" and may refuse anything else.
Your best bet is to figure out what you can supply most consistently...and then make every effort to stick with it. If you choose live, and one week the pet-store is out of live mice, I personally would probably just skip that feeding, rather than try a different type of prey. Of course, I would first make every effort to find a live mouse somewhere else.
Anyhow...choose what you can be most consistent with...and then just stick with it.
Re: Switching prey items?
IMO ...
if you have one that will eat F/T i would leave it on F/T and check into
finding a place that you can buy in bulk either online or local.
personaly i have found it to be cheaper to feed F/T rather then live as well as
less worry some.
here where i live cost of a small live rat is $2.99 each (closest place i can find small rats) vs. F/T (from American Rodent Supply) 1.00 each
when you feed F/T you wont have to have a place to house the mouse/rat if your snake refuses to eat, you wont need to feed it, wont have to worry about being in the room till the snakes eats ect...
personaly i rather feed F/T over live for many reasons, but in the long run that will be a personal choise you will need to make, weighing out the pros and cons to both live vs F/T as well as what would be more readly avaible for you.
best of luck be it F/T or live :)