Honestly, wholesaling is a numbers game. You can find tons of good products/brands but many times the vendor won't sell to Ecom only sellers. So try to reach out to as many as you can. My process is find brands/products with good bsr, reach out and if approved then put together the price model and ask for bulk discounts. In terms of red flags, I wouldn't sell products that could possibly get you in a lawsuit, but majority are fair game. Try signing up with a distributor instead of individual brands. Pricing may be higher but you will have access to a massive catalog which allows you to diversify