Diploma

Scope, job opportunities and salary after graduation in agriculture:
Lots of Government as well as Private Job opportunities are present in front of Graduates. Talking about Government jobs, State Agriculture Departments recruits Graduates to fill up Officer level posts. Government Banks also recruit

Yes, you can as the candidate have passed 10+2 from a recognized board and should have good communication skills.

For short term, it may be beneficial, but if you want to make a career in this field, then getting a degree in Travel and Tourism would be beneficial. There are specializations in Management as well for these courses.

Yes, you can get admission in DTU in 2nd year of lateral entry B.Tech programme. You need to appear in LEET exam of DTU and get your name in merit list.

There is lateral entry for B.Tech students but I'm not sure for B.Arch.

Yes, you can join the cabin crew diploma course after class 12th. Please go through the link below.
https://www.shiksha.com/aviation/cabin-crew-air-hostess/colleges/colleges-india

Yes, but if you aren't much with a Background go for a graduation, it is much better.