Civil Servant (IAS/PCS) exams

It depends upon your ability, preparation strategy and many other factors. There are some other IAS also, who got in 2 to 4 attempts because they were doing job at the same time.

In 2015, out of 1750, the cut off marks for the Mains was 678 for the general category, which is 38.74 percent.
In 2014, the cut off for the general category was 678 out of 1750 that is 38.74 percent.
This was sharp increase from 2013, when the cut off marks was 562 out of 1750 that is 32.1 percent.

You can try online coaching, as the class will be at your door step and you need not to spend money and time in commuting, relocating, etc.
You can check the below mentioned link:
https://www.wiziq.com/courses/search.aspx?qry=IAS coaching

For IAS, you need to prepare for 6 months. For first 3 months, you need to study for approximately 6 hours a day, while for last 3 months you need to study for 12 hours a day.

IAS surely means brilliance in your academic career. You should try for a distinction in your BA. It will become a good launching for you. IAS implies every day work. So, nothing is wasted.

You have to show a consistent academic performance for a good future. You have to get a first class throughout your career. So, work for it now. You need to take care of your academics. There is no separate preparation for IAS.

It depends on your dedication, but on an average 2 to 3 years are more than sufficient for IAS.

Yes, you can prepare for UPSC after completing B.Sc.

IAS implies hard work with all sincerity. So, estimate your capacity for hard work. If you are satisfied with yourself, you are bound to succeed. Your desire for quality matters more. All other things come automatically. How many man-hours can you spend at a stretch? If you're confident with yourself, you will find a methodology soon.

It is not a problem, combining all these pursuits. Even after joining service, you can complete your research and submission of the thesis. Such instances are in plenty. Go ahead with whatever you desire.