khutba

Q: I'm stuck in a weird situation. I am studying in Birmingham city university. Alhamdulillah we have been told by our elders not to criticise people from different school of thoughts than yours. I follow Deoband school and go in tabligh jamat very often. In my university saalfi brothers are trying to take over, like they made the Islamic society majorly run by them. Problem is'nt that but the problem is that for Friday jumma from last 12 years an Imam has been coming. They asked him to not come and they (students) have started to lead the jumma. They do the juma kutba which is after second azan in both English and Arabic, like they start in Arabic a bit and mostly start speaking in English. My fist question is that is khutba like this valid, secondly I've seen them doing maasa on normal socks not the leather ones and they lead the prayer is that acceptable.

Q: Is it sunnah for the Imam to start ascending the mimbar with the right foot in order to give the Jumuah Khutba?

Q: Please can you advise if a person's Jumuah Salaah is accepted in the following situations and if not, then how should one make up for it:

1. A person arrives late and the first part of the khutbah has finished?

2. A person arrives late and the khutbah has finished, but manages to join in the first rakaah?

3. A person arrives late and misses the khutbah and first rakaah of Jumuah Salaah?

4. A person arrives on time for the khutbah but does not listen attentively to the khutbah.

5. Please can you advise if the second part of the khutbah is one which is read everywhere and does not change or are their different versions?

Q: Is it a requirement for the khateeb to perform the Jumu'ah Salaah as well, or can anyone perform the Salaah?