You've got questions, I've got answers!
1. I just realized I'm totally out of lemons and had planned to make your tofu yogurt. Can I substitute another freshly squeezed juice, such as orange or lime?
While I haven't tried it personally, I have heard from other Herbies that lime juice does work for that recipe. I'm not aware if anyone has tried using orange juice, but I think it would be too strong unless you blend it with other fruits.
2. What do you think is the best vegan "hamburger" crumble available?
I don't buy any of the commercial ones -- mostly because they are outside of my budget or are not available where I live -- I live in a very small town. I make my own bean burgers, etc (recipes in my cookbooks and on my blog) and I have a recipe for "beef" crumbles in my first book, The Happy Herbivore Cookbook on page 140, that I use all the time.
3. Do you happen to know if using oil externally as a skin cleanser or as an "oil pull" is as detrimental as consuming it?
I don't think so, but I'm not sure. I've never used oil on my skin, except a tiny bit of coconut oil on my elbows, but I switched to unscented shea butter a while ago. Our skin is our biggest organ, and it does absorb, but still I don't think it would be the same as ingesting it.
4. I was just wondering what you do for exercise, especially while traveling.
I snowboard in the winter and do water sports in the summer, I just keep an active non-sedentary lifestyle.
5. Is there a big difference between regular flour and the pastry flour or can I use them interchangeably if I don't have the pastry version? Thanks for your help!
Yes, there is a big difference in the types of flour and which ones can be easily substituted for one another. Whole wheat flours are denser, more grainier and often more thirsty, so they need more liquid.