Using a black pen

Q: “On one occasion Shaykh Zulfiqar Naqshbandi Saheb (db), while on a journey to Zambia, requested a pen from one of his Khulafa. The Khalifa took out a Blue pen from his pocket and presented it to the Shaikh. On seeing the pen, the Shaikh said, “Subhanallah Mawlana saheb, Are you not aware of the ink colour which is Sunnah?” At this the Respected Khalifah said, that he was set aback by this, and it put his mind and heart to distress. He began thinking, what is the Sunnah ink colour? Then the Shaikh mentioned that “Haven’t you read, the colour of Ink that Nabi (Sallallahu Alayhi Wasallam) used on the occasion when he wrote letters to Kaiser and Kisra?” And then, the Khalifa remembered that, Nabi (Sallallahu Alayhi Wasallam) had used black ink.” 

Mufti Saheb, in light of the above, will I be rewarded for using a black pen  instead of another colour if my intention is to gain the Pleasure of Allah Ta’ala by following the Sunnah?

I have no problem with Hazrat Shaykh Zulfiqar Ahmed Naqshbandi (db), it is just that this the first time I became aware of this particular Sunnah. In addition, I thought Nabi Muhammad (Sallallahu 'Alaihi Wa Sallam) was illiterate and thus unable to write. Therefore, I am uncertain. Please advise.

Spots on one's underwear

Q: When I get up in the morning, I see some little spots on my underwear. I am unable to decide if these are the spots of mani or any other liquid.

But I can give some detail about I experiences related to this problem:

  1. I see these spots daily.
  2. I feel nothing all night and no wet dream.
  3. When I wash my private part, it seems like something oily is applied on the top of it.
  4. These spots are white.

​Please tell me if I have to make ghusal daily or just change my underwear after cleaning my private part?

Gargling the mouth and cleaning the nose while fasting

Q: 

  1. A person begins fasting in the state of janaabat. Regarding ghusl in this state, is the ghusl valid if the water does not reach the inside of the throat or the inside of the nose (i.e. these actions cannot be exaggerated out of fear of the fast breaking)? Will the ghusl be valid if the water did not reach deep into these areas? Or would the person make ghusl washing the nose and mouth as in wudhu and upon breaking the fast would the person then gargle the throat and wash the inside of the nose properly?
  2. A person forgets that they are fasting, and thus gargles and washes the nose intensely so that water is accidentally swallowed. Is the fast broken, bearing in mind that the person forgot that s/he was fasting?

Qadha Salaah after fajr and after asr

Q:

  1. Can Qadha salaah (esp. Qadha Umri) be performed after the fardh of fajr and asr? If so then what salaah are not permitted at that time?
  2. On safar, a person does not perform a salaah e.g. asr. On returning home from the journey, does one perform qasr (i.e. 2 rakaats qadah) or 4 rakaats of qadah?
  3. Likewise, if a person omits a salaah e.g. asr in his hometown, whilst on safar does the person perform 4 rakaats of qadah or 2  rakaats of qadah for the salaah missed whilst still at home?