Re: Ideas and questions before I adopt!
1. There isn't a specific amount, some people don't feed extra things at all. Mealworms are high in fat, so you want to make sure you don't feed too many. Crickets are a good option, since they are low in fat. The people that I personally know feed a few insects daily, and treats (veggies, fruit, meat) about every other day.
2. It can be VERY hard to get the smell out of those. Hedgehogs have a MUCH better sense of smell then us, so personally, I wouldn't do it. Instead try washing a prescription bottle, putting beads, rice, tiny rocks, etc. in the bottle and closing the lid. Make sure you cut the toilet paper tube down the middle so they don't get stuck.
3. Making a ball pit would be hard. The hedgehog won't want to walk on top of the balls, so you could really only have a few so he/she could push them around to walk on the ground. But dig pits works really good. An easy method is to put fleece strips into something, such as a kleenex box, litter box, cardboard box, or making a box out of coroplast. Keep in mind, if you use anything that is cardboard, it will need to be replaced. I think a section of the cage with a few balls would be a good idea, but not a lot. If you hide treats in there, he or she can push them around to find the treats.
4. You do need thermostat. So if you can't find one you will have to order online. I live in Canada and I've seen them at Petco, Petsmart, Petland, Petcetera and other small pet stores. I guess you're just don't carry them. But you do NEED a thermostat. Also, you don't want a heat mat, they only heat the floor, not the air. Hedgehogs need the air to be warm. You also need to have a thermometer in the cage.
5. If it's fleece you don't need to sew. But if you use other fabrics you will need to because they fray and the strings get caught around the hedgehogs foot which can lead to amputation. Honestly, so many people wash them with their things. There is nothing gross about it. Before you wash them you either take them outside and shake the poop off, hold it over a garbage and shake the poop off or pick the poop off with a kleenex. They aren't going to be gross. But if you do wash them in the wash you, you have to use non-scented laundry detergent.
6. You don't need to do that. I don't know anyone who has. Fleece is soft and absorbs well. When you put the fleece in the cage, make it a double layer instead of a single layer. So when you cut it, cut it twice the length of the cage. Tip: You might need to put heavy items around the edges or corners to prevent him or her from going under the liners, such as rocks or tiles.
7. Never use hamster balls, they are dangerous for hedgehogs. They get trapped in the smell of their pee/poo, their feet can get caught in the slits and they can't get out of the ball if they want. Instead, but a small animal playpen and put him/her in there while you clean.
Also, almost all of the books and other websites will give you wrong information about hedgehogs. This is really the best website to be learning from.