Tier 2 to Global Talent

Hi, I am currently on Tier 2 (General) or Skill worker visa which is valid until Aug 2024, there after I will be eligible for ILR. However, as my wife joined me after 5 months so would have to apply for Tier 2 visa extension. Since, I am working as a Lecturer, I am planning to apply for Global talent visa. However, would need suggestion regarding the following,
1) For endorsement, do I need research funding or proposal which I need to submit to Royal society? I am currently on teaching only contract and so have no research work, apart from what I did during my PhD.
2) If I switch from Tier-2 / Skilled worker visa to Global talent visa can I use the previous IHS reference number or claim for refund?
3) I have recently applied Tier-2 dependent visa for my new born. The decision is pending even after 8 weeks, but can I withdraw his application and apply together for Tier-1 ? If so, can some one suggest how should I contact UKVI to withdraw his visa application and if I will get the IHS and visa application fee back?

I will be grateful to anyone who could guide me in the right path and clarify my doubts.

Thanks in advance
Rahul