B1/B2 Visa after F1 Visa

[vids]

Just the past week I got an F1 visa issued for the Fall 2017 program. The program start date is in the third week of Aug 2017; however, another opportunity came by few days ago that requires me to travel to one of the conferences in the US as a speaker in the month of September 2017. The catch is I am now thinking of reapplying to the program next year, and not using my F1. And rather requesting for a B1/B2 Visa to travel to the conference. I have the following questions:
1. Can I obtain a B1/B2 visa, as I have an F1 already.
2. Will my F1 visa get revoked, if I am to get a B1/B2
3. Should I cancel my F1 before applying for B1/B2. If yes, should I write to the college and request a letter.
4. Will my decision to obtain B1/B2 and cancel (or not use) F1 impact my chances of obtaining F1 next year to the same college.
5. Although I would be attending a conference, I do not intend to seek support from my organization for the travel or visa papers. Does that mean I can only apply for the Visitor's visa (B2)
6. The conference lasts for only 4 days, can I travel a week in advance to the conference or extend my stay by a week.

Also, I plan to book my return ticket prior to my visa interview, as I have a clear intent of returning and resuming my work in my country.

I'd appreciate any guidance on my doubts, and the potential challenges that might come my way.

[inadmissible]

1) Yes, although the burden of demonstrating strong ties to your home country is higher with B visas than for F visas
2) No
3) No
4) No
5) It is still a B-1 purpose regardless of who pays
6) Yes

[vids]

1) Yes, although the burden of demonstrating strong ties to your home country is higher with B visas than for F visas
2) No
3) No
4) No
5) It is still a B-1 purpose regardless of who pays
6) Yes

Thank you for responding. In response to demonstrating strong ties to my home country, what documents might your recommend that I carry. Few other things to my profile:
1. I work at a reputed product-based company in my home country.
2. I have social ties here, although not married yet.
3. I have sufficient financial background.