Switch from the Tier 1 GE visa to Tier 1 E visa

Dear experienced visa applicants,

I am currently holding the Tier 1 graduate entrepreneur visa (hereinafter ‘Tier 1 GE’) for the first year and intend to switch it to the Tier 1 entrepreneur visa (hereinafter ‘Tier 1 E’) before it expires. I do not want to extend the Tier 1 GE for the second year.

I have read the latest visa application guidance published by the Home Office in October 2019 and know that I am entitled to do so. However, I still have a couple of questions to ask.
If any of you here has gone through a similar experience and could provide me with some tips or suggestions. I would be very grateful.

I have got three broad questions are:

Q1: Is there anything else is needed, apart from the following required documents?

1) Passport
2) Bank statement with maintenance fee (over 90 consecutive days) with the required amount under my name
3) Bank statement about investment capital (over 90 consecutive days) with the required amount under my name
4) My UK higher education degree (it might not be required)
5) Business plan

Q2: According to the Home Office guidance, an initial applicant for the Tier 1 E visa is exempted from the entrepreneur genuine test interview if you do it in the UK and from the Tier 1GE visa. Is there any of you (who are under the same situation) has been invited for this interview even if you are the initial application, which means you apply for it in the UK and switch from the previous Tier 1 GE Visa)?

Q3: The new application procedure askes an applicant to book an appointment with UKVCAS centres. I intend to do the cheapest option, which is to book a free appointment with a core centre. Therefore, I need to upload all the supporting documents prior to the booked appointment. May I ask:

1) Will it be problematic to upload a PDF document to the UKVCAS system even if it is less than 6 MB? (UKVCAS says the document cannot exceed 6 MB).

2) Apart from the passport, the received booking confirmation page, will I still bring all the uploaded supporting documents to the appointment?

3) I have never used the new UKVCAS system before, could anyone tell me what you are expected to do there (say in a core centre).

As I assumed, you go to the booked appointment, submit your passport, check your self-uploaded supporting documents and then get your photo and fingerprint collected? Anything else will be asked?

Thank you so much in advance.
Frank