Taking a loan from someone who took a loan on interest

Q:

1. If I borrow a certain amount of money from a person with the intention of paying back the exact amount to my lender but the money that has been lended to me is money that has been borrowed by my lender that has agreed to pay back with riba to his lender. Can I use the money knowing this?

2. If I lend a person money but the person pays back my money from borrowing from another person with riba? Can I accept?

3. If a person gives me a gift but I doubt if the gift is bought from haraam money. Can I take it?

4. I lend someone $180 but they pay back me $200 without me asking can I keep?

Finding wadi on one's ihraam and clothing during hajj

Q: When I was performing Hajj, in mina, muzdalifah and throughout that day where you stone shayateens etc... I noticed that before and after urination wadi has come out of my private part. I am also sure that wadi touches the ihraam which means that my ihraam may also be not clean during that time. I am worried that my hajj may not have been accepted or may be I have to pay for damm (hajj penalty)?