B.Ed

M.Ed is a Master course that can be pursued after you complete B.Ed. Hence, there is no comparison in the two, however in term of acceptance then definitely it is always good to go for M.Ed after you complete B.Ed.

Yes, there any many colleges in Indian which can offer you campus placement.

After doing M.Sc. and B.Ed. with mathematics you can try to be a school teacher and if you do M.Ed. and qualify NET then you can try to be a college teacher. There are just some scopes in teaching field.

You can either go for M.Ed. or PhD. However, M.Ed. will consume 2 years and PhD will consume good number of years. Instead, you should go for some certification courses like spoken skills training in English or some voice and accent training. In short, you can develop yourselves as a trainer. However, since you are already MA, B.Ed. you can go for CTET. Teaching English would be the best profile for you as you can get into govt. jobs as well.

Theoretically, you can do both degree simultaneously. Majority of universities do not allow students to register for two courses simultaneously unless they have dual degree programs. However, you are advised to check with targeted universities about feasibility of doing two degree simultaneously where you are planning to do M.Sc. and B.Ed.