B1 to H1 process

[Sj crazy]

Hello,

I have valid B1/B2 visa and visited US multiple times on B1/B2 visa.
During my recent visit to US, an employer contacted me and he extended job offer in US on H1b and he is ready to fill h1b, the process which he mentioned is:

1. The employer will file H1b in first week of april, 2012
2. If it get approved somewhere in July/August
3. Come to US on B1/B2 visa in Oct/Nov, 2012 and start working on the project and he will extend my stay and I can stay in US till my i979/i94 is valid
4. If i want to get my visa stamped then he advise me to visit home country for stamping after 1 year of stay in US, since the possibility of getting visa stamping will be high.

Now, related to this I have below mention questions.
1. Is it a safe option, what is the risk factor?
2. What is the process of extending my staying in US, once I enter the US on B1/B2?

Thanks for reading this and looking forward for your kind inputs.

Thanks.