H1B Visa Fees payment timelines for regular processing?

My company (one of the large IT services players in India) recently seeked my acceptance to nominate me for H1B visa for FY18, .i.e, in April 2017 and also took a verbal commitment of serving in US for at least 3 years

I said yes looking at long term opportunity but I am not very sure about long term stay in near future looking at some uncertainties in personal life in next 1-2 years (was planning a job change in India itself, marriage etc)

As of now, I have given a go ahead to my company for H1B application.

Wanted to know few things specifically here

  1. I understand company will do some internal processing and get approvals but the actual application will be submitted only in 1st week of April.

At which point during the entire process, company actually pays which part of the fees?

How much company pays while submitting all the applications in 1st week of April?

How much company pays when the application gets selected in lottery for further processing?

How much company pays for final visa stamping?

I want to know these, because if I make up my mind to back out, I would like to do so as early as possible before a lot is spent for visa application.

  1. Is there any official rule in the large Indian IT players like 3 years commitment if one gets selected? What if due to some personal reason I decide not to travel or to switch job in India or to come back after spending 1 year in US? Can the company cause me any trouble?

I am referring to companies like TCS, Infosys, Wipro, Cognizant etc.

I am in a dilemma. I want to travel for onsite opportunity but not sure about long term plan due to some uncertainties in near future.

Kindly help me take a better decision.