Tier 2 Extension and PBS dependant form submission error-urgent guidance

[Npa]

I have applied for Tier 2 visa extension along with PBS dependant visa extension on 23rd June 2021. Our biometrics appointment is on 4th July.
My query:
While filling the form for main applicant:
I have added him as an additional applicant and put all the details of myself and my husband together. Thinking that it will get linked when I submit his form. While submission I chose: submitting the form for self and others.
I have paid for IHS and application for both. Our appointment is for 4th July. On submission I have received confirmation for 2 applicants, I received 2 QR codes too.
Then I realised I had not submitted his form that I had prepared separately. So when I went to submit his form, they accepted the IHS reference number, but are asking me to pay additional charge for him as applicant.

I have got confused now for:
1. Will my application be considered for me and him?
2. Few details (example his NHS visit, his previous country of residence etc) are missing on my form. Would it create any issues for the case worker
3.Should I pay for his application and submit again?

4.Will I get refunded the additional fees?
5.Is there any possibility I could amend my application?
6. Will the visa processing time be considered from 23rd of June or after I go for biometrics?

Since I have very less time left for my appointment, any quick responses would help me.

[Npa]

Dear all,
Please could someone guide me on this topic. Time is running out as my appointment is at this weekend.

Thank you for all the guidance that is always available here