Selling an item to someone not knowing whether they will use it for something impermissible

Q: 

1. Would it be halal for me to sell gold to a cash for gold place because there is a high chance they will sell this gold to a refiner, scrap gold buyer or so on and they might use this gold to make gold jewellery for men etc.? 

2. What about selling grapes to a business that sell grape related products so the grapes I sell to them can be used to make their grape juice or it can be used for their wine etc. Will the income be haram? Because I’m unsure what they will use it for.

Washing clothing that was soiled with urine

Q: My 3 month old son had a portion of his clothes wet with urine. I removed the onesie and placed it carefully on the bed with the urine part facing upwards so I could wash it. 

I fed my son and when I was done I picked up the onesie and went to wash it. Then I saw the onesie was completely dry all over and I couldn't find the spot where it was wet previously. 

Can I use this onesie now or must I wash the whole thing?

Investing in the stock market

Q: Please advise if investing in shares in publicly listed companies which sell the following is permissible or not: 

1. A Distribution/Retail business whose main business is pertaining to selling foods, cosmetics, appliances, bakery, butchery (haraam meat also sold) sells alcohol also. 

2. A mining, telecommunications or property holding companies that has conventional bank loans and fixed deposits that earn interest?