Amina Inloes

The are a number of narrations indicating that the Imams (A) had comprehensive knowledge of astrology, and you can find them in books such as volume 55 of Bihar al-Anwar. (Whether one accepts them is a personal decision, but there are no narrations to the contrary.) One narration (the "Myrobalan Fruit") implies that astrology exists as a way to prove the existence of God and the prophets' knowledge from God. 

Whether or not astrology is considered shirk has tended to depend on worldview. If someone is an atheist and believes that there is no God but that the stars and planets control their destiny, then this is shirk. If someone believes that their fate is wholly fixed by astrology, and that God cannot change it, this is also theologically inappropriate.

If someone believes that God is in command of the entire universe, and astrology is part of the divine plan, and that our ultimate fate is in the hands of God, this is not shirk.

Some Muslims today are too eager to throw around the word "shirk" without thinking about what they are actually saying.  

Most Shi'i scholars consider it necessary to remove nail polish for wudu'. (This is apart from the view of the late Ayatollah Fadlallah, who did not consider it necessary to remove it for wudu'.)

However, regarding feet: In Shi'i fiqh, for wiping the feet in wudu, it is necessary to wipe from the tip of one toe to the ankle. If one toe does not have polish (such as the little toe), one can do the wiping including that toe, and fulfill the requirements of wudu. However, that does not work for ghusl, since you need to wash everything. 

Hands: The above doesn't work for hands. 

It is not unusual for people to have a sense that something bad is about to happen, especially if it involves someone they are close to. It indicates that there is more to ourselves and the universe than what is measurable through material means. 

It is narrated from Jabir:

I sighed in the presence of Abu Ja'far (Imam al-Baqir (A)) said, "Son of Allah's Messenger, sometimes I feel afflicted for no apparent reason or I am overcome with a condition of grief such that my family and friends see it on my face."

"Indeed, Jabir," he replied.

"Why is that, O son of Allah's Messenger?" I asked.

"What will you do knowing it?" he asked.

"I would love to know," I replied.

"O Jabir," he then said, "Allah created the believers from the earth of Paradise and brought about their souls from the breeze of Paradise. Believers are thus full brothers; so, when one soul amongst this group of souls is afflicted in any place, the rest are depressed, for they are one."

It is not something that causes punishment in the hereafter, but often people are happier or more stable in life when they get married (even if it has its own challenges!).

If you are young and don't have an obvious reason not to get married, if an opportunity that feels right comes up, it's nice to at least try to explore the possibility of getting married, so you don't look back and feel like you missed out on something. But everyone has their own path in life and sometimes one path is not for everyone.

There is no Islamic problem in wearing niqab in some places but not others. However, sometimes there is a cultural idea or social pressure that someone who wears certain types of garments should not be seen differently. So you should decide what you feel is best for yourself. Sometimes an advantage of trying new clothing in some places is it gives us a chance to experiment with  it and see whether or not it is something we want later in life. 

Yes

Marriage is recommended in the sunnah, and in a good situation, can provide stability, security, support, spiritual blessings, and happiness, and women in particular (even today) tend to enjoy a higher standard of living and more security when married. Of course, sometimes it doesn't work out well.  Anyway it is optional, and some important sacred figures like Hazrat Maryam (a) were not married (in the view of Muslims). 
 

This is a Shii view, and some Sunnis debate whether marriage is obligatory or not (although a good number of Sunnis would say it is not). 

Yes

It's not unusual for people who are drawn to healing others to also have a strong spiritual side. 

If you're already on track to being a doctor and can realistically complete your medical education, it's worthwhile to finish it. This will enable you to serve people wherever you live, and also help you to have a decent income. (Sometimes, people who study Islam struggle financially.) A lot of people who study Islam have degrees in other subjects (such as engineering or medicine), and what you study now can help guide you in the future.

Although I haven't been to medical school, a lot of people seem to have meltdowns partway through, and so it's also worth considering whether you genuinely are called to a different life path, or you are just feeling overwhelmed with the stress and challenges and just need to hold on.

You can still dedicate time to worship as much as you are able (it is often about quality rather than quantity of time!) and, in the future, also on studying more about Islam.

If you are living with him and want to move away, but are financially dependent, afraid to leave, etc., the best thing is to find someone reliable who understands your circumstances who can advise you on the practical options available. 

It would also be helpful to find someone whom you can discuss the psychological aspects of your situation with, since it can be difficult to leave an abusive situation, even for someone who is financially and socially independent. 

For instance, you could speak to a trusted adult with life experience, a counselor/psychologist, or a charity worker.

If you are in physical danger or being trafficked into illegal/dangerous jobs, this is especially urgent. 

Later, you can consider how you may wish to keep ties with your father. "Keeping ties" can mean many things and in abusive situations may mean keeping more distant ties.

There isn't a religious requirement to live in the same home or be in close contact, but sometimes it can be difficult to leave a situation for financial, cultural, psychological, or other reasons. 

Personally, I would find it weird to have it around. However, according to Ayatollah Sistani and Sayyid Khamene'i, it is not necessary to get rid of statues of humans. 

Here are some historical Abu Bakrs:

https://en.wikipedia.org/wiki/Abu_Bakr_(name)

It is normal for some people to see lights, colors, and so forth when their mind is in a relaxed and contemplative state.