1. How long before she can be at home alone?
I was home a couple days, then I went back to work. They really bounce back quite quickly and if she doesn't have access to climbing up on couches or anything, she'll be fine in a few days.
2. I don't want to get her an ecollar, is there anything else I can use to keep her from licking her wound?
Rhianna never licked her wound, she had inside stitches. They sent her home with an ecollar and it was just horrible. I opted for a onesie instead, but didn't need it at all with her.
3. Are there any special foods or drinks I can give her to help with the pain? A heating pad?
They will give you pain meds to take home. Rhianna was still pretty doped up and didn't seem in pain at all even the day after. The vet told us give them if she needed them, which she didn't. Just provide plenty of love and maybe even some turkey and/or chicken. 
You'll see how quickly they actually do bounce back. Just keep her from running, jumping off things, etc.