Magento 2.4.3, various issues

The project is to first get Magento 2.4.3 p1 up and running.
We have already converted it to 2.4.6 but since there are some major changes between the two APIs must be fixed up and also some other issues due to php8.1 and removeal of zend in 2.4.6. 2.4.6 has approx 15 issues to resolve AFTER THESE issues for M2.4.3 are resolved..

# Priority Subject
90 MS1: checkout screen 2hrs
86 MS1: import script: not setting consumable items 1hrs
85 MS1: web frontend 2hrs
83 MS1: web page: menus 1hrs
79 MS1: import script: thumbnails 2hrs
78 MS1: importscript: swirl/loader 3hrs
76 MS2: payment system issues 1hrs
72 MS3: Magento is not transferring the weight to the Royal Mail module 16hrs
60 MS2: API for profile is not working 4hrs
57 Live server, 2.4.6: Optimise speed on website when we move 2.4.6 it to live 24hrs

The tasks are added in the attached Excel file. Please fill out and return to me as a detailed estimation before we agree on anything.
This job is only a few days max so it is a pretty fast job.

Also: Spare me from insane 14, 45, 50 days estimates. I have 46 years in the industry and have made too many estimates :-).