Hello SunnyUjjawal, As you know Search Engines are changing day by day with quality results but not really ignoring off page activities. If you're doing any kind of off page activities then keep in mind that work must be comes in white hat SEO strategies.
About your last question-> future of seo is bright & if search engine's are updating Algorithms; then you have too keep updating your knowledge in All Internet Marketing Key.
i read all discussion over, but from my opinion job opportunities for SEO in India are already down (as my update on SEO world) and also going to be down in 1-2 years. but not going down web design and development work till 5 years.