Relocating to Germany as a web dev — visas, freelancing and taxes?

I’m a front-end dev in India, got a few interviews with German companies and also thinking about going there as a freelancer instead. I’ve read mixed stuff online and want practical answers from people who’ve done it or hired devs there.

Specific stuff I’m unclear about:

• If I get an employment offer, is the EU Blue Card the usual route? What salary threshold should I expect for front-end roles?
• Can you freelance on a Blue Card or do you need a separate freelance visa? If freelance, do I register as Freiberufler or Gewerbe for web development?
• How does taxation work if I move mid-year? Do I pay tax in Germany only, or also back in India? Any links to clear guides or common pitfalls?
• Health insurance and bank account basics newcomers always miss?
• If I keep Indian clients while living in Germany, do I need to charge VAT or declare GST back in India?