ECAA Businessperson to Skilled Worker

I am on ECAA Turkish Business person visa type. So far I completed 3 years in the UK and I have another offer now from a big automotive company for a skilled worker visa.

The main thing is I am wondering if I change my visa type from ECAA Turkish Business person to Skilled Worker, will this restart the years count for Indefinite Leave to Remain? Or is there any possibility to combine the years we lived in the UK before the ILR application?

The other thing is it is mentioned on gov.uk, skilled worker grants 5 years residency to a person but one of my colleagues told me he has only 3 years now and they need to apply for an extension after 3 years.

As I am in ECAA Turkish Business Person visa type, is there any possibility to change this to ECAA Turkish worker visa type by counting the years?

Lastly, in case of any termination of the contract by the employee, I will have to leave the UK in 2 months as far as we know, this is the biggest risk we don't want to take because we love to live in the UK.

I am indecisive now to accept this offer and restart my 5 years by taking this risk, is there anyone out there who might have confident information about visa switch and combination of the visas for 5 years?