1-2: Basically, my understanding is that options trading would be halal. It’s halal because with options trading you’re basically paying a premium to a broker to reserve the stocks for you, then when the time comes you decide whether to buy the stocks or not. And it’s not haram to pay a broker to reserve stocks for you. As for future contracts, if the buying/selling is being conducted now, but the product/payment will be delivered in the future, then it’s halal.
4- Yes, as long as they are not engaging in harmful projects or immoral projects
5- As long as you are not dealing directly with interest and you are not directly investing on interest based transactions then it’s ok.