You might ask about this in the "Family Bed and Nighttime Parenting" forum.
One possibility is to use a sidecarred crib--either a special crib designed to be up against the bed, or a regular crib with one side lowered all the way down. That way she's still close to you, but you're safe even if you are very tired. There are also foam wedge things that are for in case the baby is rolling around so they don't roll off the bed during naps, but you could use one between you and the baby, if you did roll over in your sleep it would bump you back.
Personally, I roll around a lot more when I'm not very tired than when I'm completely zonked, but have considerably more awareness of things when I'm not totally exhausted.
Just reread your post, for naps during the day, you should be fine and the naps will help you be less exhausted when bedtime rolls around. But having a crib set up for possibly using could be good, that way if you are exhausted, you can just put her there.