[Machi604]

The rest areas are safe.. just remember to lock your doors (obviously). The drive isn't really that long so a motel isn't needed at all. You'll be fine napping at the rest stop.

Let me know what your budget is for a hotel and I'll give some recommendations.
Louise is much nicer but if you want shopping, bars, etc. Banff would be the choice.

It really depends on which lake you go to but the popular ones can be done with minimal hiking. Some are not too far off from the highway either.. Moraine Lake is one of my favs! or Lake Minnewanka.. rent a canoe and start paddling out onto the lake. Elbow Falls is pretty cool too but outside of Banff.