比方 as a conjunction/连词？？
I don't know which vocab book you are using, but to my native ears, your conjunction examples sounds a little bit weird! I would have added a 说 at the end of 比方 to mark the use of conjunction.

比方说 would mean


for example： 他去过很多国家，比方说美国，英国，中国等
if(colloquial)：比方说你是我，你会怎么办


Note that I personally have never used it in the second meaning. It is understandable, but not very common. I would use 如果/要是 instead. I also must contest the notion that 如果 is only for informal use. It can definitely be used in formal context as well, though probably less pretentious then 假使

hope it helps