Factors that break and don't break the fast

Q: If a person was fasting and icing sugar or bicarb blew and the taste went in the mouth (like through the nose) by mistake, is the fast valid?

Q: At asr time, one went to toilet and noticed a change of colour in ones discharge however one was unsure whether it was haidh or not. At maghrib time, after breaking the fast; before performing maghrib salaah; one saw that ones haidh had commenced. 

Will this fast be valid or will one have to repeat it?

Q: Does touching the private parts and pubic hair break the fast?

Q: Is it permissible to wet the miswak before using it while fasting? 

Q: My question is related to the validity of the fast. 

While doing my Kaffarah, I was cleaning my home and dusting off some shelves on the 58th day out of 60 days. Some dust flew in the air and I inhaled it. I looked the issue up in Maraqi al-Falah and it said in the chapter of that which does not invalidate the fast, "dust or smoke alongside smoke from wood or incense entering one’s throat without one’s doing". 

Here, it is mentioned, that smoke and dust which is inhaled by ones own doing will invalidate the fast. Does the aspect of causing it oneself only apply to smoke or does it apply to dust, too? 

Is the scenario I described classed as deliberately causing it myself? Do I have to restart my Kaffarah because of the fast becoming invalide or is the fast still valid?

Q: I had used an inhaler (pump) just before subh saadiq. After subh saadiq, I got a taste of the liquid medication in my mouth. Is my fast valid?

Q: Is it permissible to apply oil to the scalp or body while fasting?

Q: Will the fast break if sperm comes out while urinating?

Q: Would it be permissible for a female who needs to use a disposable catheter to use it while fasting, if she needs to use it due to medical reasons. The catheter is inserted into the bladder, using a lubricating gel.