Exam

Keep studying and keep your position alive as you had in your previous school.

Government jobs have a very complex problem which is delay in results, verification and joining processes. Those who have cleared are waiting for their documents verified and those who have got their documents verified are waiting to join. It's normal
So, have patience and keep checking for updates.

I had similar kind of questions when I was in your class. Class 11th is way much important than we think, you'll need every sentence you've read in class 11th later
You should stick with NCERT books and keep solving exercise, intext and additional exercise questions too. You'll find same exact questions in previous year papers. You may download it online.

You can appear in NDA written examination, and if you get it cleared, you'll be called for SSB interview, but the minimum height will be called when you have to go through physical test and luckily minimum height for girls in NDA is 152 cm currently
In short, you could appear in NDA for sure.

Nope, As in my knowledge the latest information says that you can get your college transferred only when you're in your first year.

Focus on your board exams, as you need it.

Given below are some of the top private ayurvedic colleges in India
Shree Guru Gobind Singh Tricentenary University, Gurgaon
Tilak Ayurved Mahavidyalaya, Pune
Patanjali Ayurved College
K G Mittal Ayurvedic College, Mumbai.

There are several websites available on internet, but I can't paste an external link here for the question papers. You can simply Google it.

Yes, You need to register at Indian army website and you'll be informed about your SSB interview through email. Last date for registration depends on date of result declaration. Refer the official press note released by UPSC in which your roll number was displayed.