Pooping once a day seems fine, especially if you are feeding quality food. Generally the more active my dog is, the more she pees. No one wants to be running around with a sloshing bladder! She might pee twice in the same walk (about an hour long trip) but hold it all day when she's just couch potato-ing around the house.
Are you walking & exercising her, or is she just being let out to do "whatever" in the backyard?
Also I wouldn't worry too much about snakes. Most dogs aren't as allergic to snake bites as humans are. Mine has never met a live snake, but she's scared to death of the dead ones we have found in the road - instinct I guess? I believe she may have spotted a snake at the edge of our yard yesterday, and she barked at it and wouldn't go near it, but I never saw it so I don't know for sure.