You have a question, I have an answer.
1. How often do you go grocery shopping?
When I lived in NYC I went every day. This was partly because my kitchen and fridge were so impossibly small that I really didn't have the ability to stock up. I also lived within 5 minutes walking distance of several markets, grocery stores and a boutique health food store, so it was really easy for me to get what I needed on the way home. (Note: I don't recommend this, I found I spent too much money this way).
When I lived in St, Maarten I went almost every day. We had a bigger kitchen, and more storage, but since the store received new and different shipments several days a week and some foods sold out fast -- I was always there, ready to get my hands on cartons of almond milk, or fresh produce or bread. The market was also within walking distance, which made it convenient, at least. Living on an island has a lot of frustrations, a big one being that all food is flown in and frequently runs out.
Now that I'm in Colorado, however, where the grocery store is 5 miles away, I try to only go once per week. I find if I plan my meals out (which I do with HH's Meal Plans!) I can get everything I need in one trip. I can't really cut it back any more than that, our fridge isn't big enough to hold 2 weeks worth of fresh produce. Scott & I have large appetites and really love our salads and greens.
2. What protein powder do you recommend?
Please see my post on protein - it discusses protein powders.
3. Are 1-minute quick oats an okay substitute for rolled oats?
It depends on the recipe. Rolled oats can be turned into quick oats, though. See my post on oats, their differences and when you can substitute them.
4. Any tips for multiplying the single-serving recipes?
Sadly, all the single-serving recipes are true single servings which means they don't really translate when multiplied out. If you want a full pan of brownies, try the Fudgey brownies (p. 207 HHC) and if you want a full pan of pumpkin muffins, try the maple muffins (p. 46 HHC). I also have a recipe for a full pan of blueberry muffins and a pan of fruit crisp on this blog... so basically, all my single serving recipes have a full serving cousin!
5. How can I get my Hippie Loaf to firm?
First you want to make sure you really chop and mince everything well. Next, You really want to pack it down tightly -- really smoosh it in there. Then let it cool before trying to pry it out. Mini loaf pans work better than standard loaf pans (cook time is about 5-10 minutes less) and you can also sub whole wheat flour for the brown rice (if you're not GF) and that helps bind it all together.
Mini-loaf! And also an example of do as I say not as I do -- big carrot chunk, ugh!