Hi Lauren,
I would like to be of help.
**Yes you can take a bus from La Paz to Santiago. Altought it would take maybe 2 full days and a very winding mountaneous road. I am sure we can help you purchase that bus ticket.
**You can cross Lake Titikaka two ways:
a) By bus from La Paz to Puno (@ 9 hours)
b) Private Transfer with stop in Tiauhanaco (reccomended)
c) Hydrofoil from Copacabana-Sun Island-Puno (you can do this on 1 day, or 2 days with overnight in Sun Island). Most expensive options but the best.
**I dont think there is any website wth bus routes. Some bus companies are "Ormeño" or "Cruz del Sur" . They might be of help but there websigths are basic and hard to navigate.
**Rio-Lima? You have to fly ... international flight (we can quote you). Only option at this moment.
Hope this helps with your travel plans and do not hesitate contactign us at
www.peruforless.com or at
richard@peruforless.com
enjoy ....