Career

Be an engineer or being in banking field, both are different prospects. So, my advice is think in your mind what you want to become and choose accordingly.

As you have experience in commerce subjects (B.Com), banking will be easier for you. Web and graphic design is altogether a different stream, you need to put efforts to learn computer skills like C/C+, PHP, .Net to become a skilled web designer. In my view, you should opt for banking.

Unfortunately, most people are lacking in minimum values, thus keeping the country in continued misery. So, I say that you can benefit the country greatly, if you are just honest.

Yes, it is. Are you looking for merchant navy or Indian navy? If you get selected for Indian Navy, then it will give you a stable job with lots of adventure. It brings in a lot of prestige also.
Merchant navy enables you to earn a lot of money and visit many countries. Having said so a career in navy means staying away from family for long time and being cut off from shores for days. If that suits you, then there are no reasons why you should not opt for it.

You need to study physics and mathematics and do sufficiently well to pursue a career in astronomy. The options are few, thus competition is fierce.
You can check the below mentioned link:
http://www.iiap.res.in/opportunities/career