Tahaarat

Finding blood on one's clothing after slicing meat

Q: I work as a blockman in a butcher. Due to the work environment I always get blood on my clothes. If I see it, I rinse it before I read salaah. Sometimes I only see some blood spots after I had read my salaah.

1. If I see blood stains (from meat carcass) on my clothes after performing salaah, is my salaah accepted or should I repeat the salaah?

2. Is blood from the carcass paak or napaak?

3. Do I have to wash or change my clothes before performing salaah if it has blood stains on it?

Checking to see if mani was discharged

Q: My question is regarding madhiy and maniy. I read on a trusted website, that, if a person feels discharge come out and they forget to check it before doing istinja but can tell from washing that no discharge has come out then ghusl is not required. This is only because I get bad thoughts that come to my mind and I always check to see if maniy has come out, but I see nothing. 

Washing impure water and saliva of a dog from one's clothing

Q:

1. If a person feels splashes of water on the uncovered part of his body, like on his back while making istinjaa, that water is impure and napak. How do we clean that part of the body?

2. If a dog sneezed on my clothes but I am not sure if anything came on my clothes because the dog was some distance away. How do I clean my clothes and the things which I will use to wash my clothes, like the bucket, etc?

Repeating salaah if one finds impurity on one's clothing

Q:

1. If one finds any impurity, like a small amount of stool on his clothes, would the clothes be considered napak and would the prayers offered with such clothes need to be repeated?

2. What amount of a najasat renders a cloth napak and impermissible to pray with?

3. If I need to repeat the prayer, would only the Fardh and witr be repeated or also the sunnat and nafl?