Do I have to file a Change of Status from B2 to H4 atleast 45 days prior to I94 expiry date?

No, you can file it as long as she is in status.

F-1 visa student overstayed 14 days in US, he left already. But what will happen if he want to apply new visa?

You get 30 days after the programs ends, so perhaps he did not overstay at all. Moreover, unless there is a finding he was out of status, there is...

Am I allowed to have a Driver's license in Iowa after marrying to US citizen ? what are the requirements?

Doubtful that you can get a license if you have no valid immigration status.

Partner from the US wants to open a company there with me (I am from Greece). Can he open it alone and then hire me?

If this is for you to immigrate, you need to clarify what sort of visa you want, investor, trader, transferee, special worker, etc.

My sons father was deported a few years ago but he worked and paid taxes for 16 years.

That is a question for social security, not immigration.

My wife wants a divorce and i didnt even get my temporary green card??

So long as your charges are not resolved the application cannot be approved and can be denied. If are divorced or your wife withdraws the I-130,...

F1 visa changed of status to H1 then H1 revoked, can I regain F1 status?

You need a new I-20 if you ceased to be a full time student for a period of time.

Speak with your accountant, but I understand if you are married you are required to file joint taxes.

Immigration

It depends what his current status is. Until and unless a judge determines he violated an order of protection, your allegation alone is not...

If my H1B is expiring in 45 days, Will i be allowed to enter US? I shall file my extension after my entry inot US.

If the visa is not expired, there is no reason why you should have any problem being admitted.