1. no, and most humi's now are MDF with veneer except for the tray, so wiping is mostly irrelevant.
2. yes
3. yes, at least for the winter, assuming it is dry wherever you are, and assuming you're going to be opening and closing your humi often.

Just keep the cigars in cello until you learn when they should be out of cello, and you'll be fine.

... and minced garlic doesn't work as well as fresh crushed garlic in my experience.