F-1 to J-1/H-1b

First I would like to give a brief history abt my status.

Initially I was given visa for 3 years in June 2004 (which expired in July 2007), when I first came to US to Wichita State University (Kansas). But I graduated in October of 2007 and had an OPT for one year that lasted for 12 months. (expired in October 2008). Then I changed to Kaplan in New York City(again F-1) and got a job starting this July that requires a J-1 visa. My concerns are -

1. How do I apply for change of status from F-1 to J-1?
2. Do I have to go to US embassy outside US to get that done (I live in US)?
3. How long will it usually take for the change of status and what factors does it depend on?
4. The Visa sticker in my passport expired, so will I have any problem when I apply for "change of Status" from F-1 to J-1? (earlier I was told that D/S stamp on the I-94 counts and not the date on the visa)

Thanks in advance for any help whatsoever,

K

If you wish to petition to change your status while in the United States, file a petition to change your status with the USCIS. If you wish to leave, then leave, get your J1 and reenter on your J1. Look up processing times here.

I can't see your passport from here. I'm going to assume that you're presently in status. If not, consult an immigration lawyer.

Dear Legal Help,

I am a physician currently on F-1 status. I got a job starting this July and the hospital sponsors H-1B visa. But I do not have my USMLE Step 3 result yet and so, decided that I make my application ready for J-1 as well, i.e., have the document DS-2019 ready.

So, my doubts are -
1. Does getting a DS-2019 form ready for a J-1 visa eligibility hamper my chances of applying for a H-1B visa. I mean, will the USCIS people know that I am applying for both an immigrant and non-immigrant visa at the same time (even though I wont be applying for an appointment till early June, 2009) and if they do know about this, Is that a problem?

2. Suppose I stick on taking the J-1 Visa, how long does it take to change my status from F-1 to J-1 (USCIS website shows a time lag of 3 months for change of status). Is this a realistic number?

3. If the time to change my status is too long, then is going to canada a good option to get J-1 visa stamped? Do US embassy ppl in Canada mandate going back to home country for J-1 stamping?

4. I am currently residing in US and plan on going to Canada for stamping. How early can I go for visa stamping and return to US, my job starts from July 1st. (i.e., is there any 30-day kind of rule to enter US after stamping?)
Please advice,

and thanks for going through my message.

Thanks - K