Dear ajosephhh,
1-I uploaded Scan copy of my own Bank Statements. You can Upload any documents(Multi pepers) related to Proof of supporting Funds, such as Sponser letter, Property peper, as well as Bank statement. As long as they have to be in one file.
2- Yes, It is, You have to write in Your native language as well as english. If you do not have a child then as I told you when you agree (by ticking yes) that the information you have given is true, that means you sign both of the form. You do not need to sign any where.
3-
A- Not for us(If you are still being said to upload it then you have done something wrong. go back to the form you filled and refill out the related question.
B- It is for SOP and anyother supporting letter
I hope, I have been able to explain.
If you still need to ask me anything please feel free you can ask what you wish to