Person's dua being rejected due to consuming haraam

Q: Prophet Muhammad (ﷺ) mentioned [the case] of a man who, having journeyed far, is disheveled and dusty, and who spreads out his hands to the sky saying “O Lord! O Lord!,” while his food is haraam (unlawful), his drink is haraam, his clothing is haraam, and he has been nourished with haraam, so how can [his supplication] be answered? 

Question: 

1. Does this hadith mean that it is "impossible" according to Islam that such a person's supplication (dua) will be accepted by Allah? 

2. According to Islam, can the supplications (dua) of such a person whose income, food, clothing are haraam be accepted by Allah, not because the person deserves to have his supplications (dua) accepted, rather due to Allah's infinite kindness, generosity, mercy?

Men wearing yellow clothing

Q: I have a question regarding the ruling on yellow clothing for men. 

Some hadith mention the Prophet ﷺ forbidding garments dyed with yellow saffron (muʿaṣfar), while other discussions mention yellow clothing in general. Could you please clarify: 

1. Is the prohibition specific to garments dyed with yellow dyes such as saffron or wars? 

2. Or does it apply to any garment that is completely yellow, regardless of how the color was produced? 

3. According to the Hanafi madhhab, what is the ruling for Muslim men: haram, makruh tahrimi, makruh tanzihi, or permissible? 

4. Does the ruling differ between plain yellow clothing and clothing that is only partly yellow? 

Shopkeeper allowing one to take items and put the money in the till

Q: I work as a teacher at a Madrasah. The Madrasah has a tuckshop. When I buy from the tuckshop, the shopkeeper (an elderly Moulana) allows me to take what I want to buy and pay the money directly to the till. In fact, he told me to do this once or twice. There is no loss to the tuckshop in my doing this. Generally, the shopkeeper doesn't even know what I bought since I paid directly to the till. Is this permissible?