Irregular bleeding

Q: Kindly advise me on the following:

A womans last haiz ended on the 01/02. On the 03/03 at 6:35 pm she noticed some blood, however the bleeding did not continue and she continued to have a clear discharge in the days that followed and continued with her salaahs. On the 05/03 at 6:35pm she started bleeding as normal. From which day will she consider her haiz to have started.

Burying hair

Q:

1. Must the hairs that collect on the comb/brush be buried?

2. Must the hairs that fall out when combining/brushing the hair be collected and buried?

3. Must the hair removed from the eyebrows, nose, mustache, chest, legs, etc. all be buried?

4. When having a shower/bath, hairs that fall off sometimes tangle up together around the drain. Must this be buried?

People congratulating one on one's birthday

Q: Before I had an idea about not celebrating birthdays, but on my first birthday in university, I gave a treat thinking that to feed someone is good, but I don't know if it's correct or wrong! Now, my second birthday is about to come and I don't know what to do if they greet me on my birthday, Alhamdulillah this year it's Sunday (I'll be on leave) but what reply must I give to the messages and phone calls from people who greet me (as I don't want to celebrate/give a treat in the name of a birthday), could you please tell me?

Avoiding interest when purchasing a house

Q: I am planning on buying a new house that costs $250,000. However, I do not have enough money to pay the full amount up front and I do not want to pay interest on the house. The deal I have worked out with the company selling the house is that I will pay $300,000 for the house but I will not pay any interest. Meaning, I will pay $2,000 every month for 150 months for a total of $300,000. This way the company will make some money on the house and I will not pay any interest.

Is this a permissible deal for me to make?

The science of tafseer

Q: I am unable to get how Hafiz ibn Kathir explained Quran in detail in his Tafseer, ie. Introduction of new words like bin kind etc... From what source ibn Kathir rahimahullah learned these things, I am very curious to know about that.

Taking medication that contains alcohol

Q: I suffer with gout and there is a Liquid Medication available (Lifetones Acid Clear) which contains Alcohol derived from Sugar Cane. 30 drops of the medication has to be taken in half a glass of water. Is it permissible to take this medication? The package insert states that the water can be boiled to 100 degrees Celcius and then the drops can be added to the boiling water therby evaporating the Alcohol, however while travelling this might not always be possible.