Do hobo spiders tend to live in rooms? And if bitten by one, would you need amputation? Same with Black widows?

No, hobo spiders (also known as brown recluse) are rare. They usually hide around piles of leaves, or rocks. You won't have to amputate anything if you catch it quickly. And trust me, you'll know if you've been bitten. The flesh around the bite will die. Lol. As for black widows, yes, they can be found around the house. But it's still uncommon.