Bachelors

Yes, you are eligible to get admission in B.Sc after completing class 12th.

You won't find any in SPP colleges. You will find certificate programs like mechanical engineering technology. Bachelor's degree are also offered but not in aerospace engineering. You will find the same only in the universities - Carleton University, Ryerson University and University of Manitoba to name a few.

If you study in USA you will be eligible for practical training visa in the field of your specialisation. You can work maximum for 18 months under this scheme. Your employer will have to file your H1 visa. If you are lucky in H1 visa lottery then you can work for 5 years more in USA. You may visit USA embassy website for further details.

There is huge demand and supply of CSE professionals in USA. Most of the demand is filled by Indian IT companies by placing IT professionals in USA. You will definitely will able to get job in USA after CSE graduation in USA universities. But you may face visa challenges to work in USA. Getting H1 visa to work in USA is becoming very difficult nowadays.

By far USA, home to MIT, Caltech etc. But for job opportunities and PR USA is very tough and competitive. You must excel in all fields. In that case Australia can be another option.

Hi, Yes you should go for 3 years LLB program it also a great career option. 3 years LLB program is available after graduation. Incase, if a person opts for BA + LLB or BBA + LLB course then the duration is 5 years however, after graduation it is 3 yours. There are lots of good colleges I.e private and public both such as faculty of law, National Law School of India University, RNB Global University etc which you can consider for your further education.
you need to clear for CLAT or LSAT exams for admission in law colleges and be sure that the colleges are approved by Bar Council of India.