Have B1, Do I need B2?

[asheet]

Hi

I have B1/B2 visa 10 Yrs. Visa type is 'R'. Have travelled on Business to US 3 times since Vida issued in 2008.
Now I want to go on a holiday to USA with my family for 3 weeks.
1. Do I need to apply for B2 visa separately or my existing B1/B2 will suffice?
2. What is 'R' in Visa category means?
3. I have I-134 for self & family members. Do I need to submit my I-134 also if I already have B1/B2 visa?
4. My elder son is studying in another city & is 19Yrs old. Can I file his I-134 or he has to visit US consultae in person for B2 visa?
5. Other Son is 14 Yrs old. Do he need to visit Consulate for B2 or my wife can only visit & file B2 for herself & both sons?
Pl revert asap

Thanks

[immihelp]

1. Suffice.
2. R = Regular (Not Diplomatic etc.)
3. No.
4. If you don't live in the U.S., you can't fill I-134 for anyone.
5. Yes, he needs to visit.

[asheet]

Addl queries

Thanks for quick revert

Since we are visiting USA on a holiday & will be staying with my brother, I have :-
1. Invitation letter from brother
2. I-134 for self & family from my brother
3. Bank Stt & Support letter from brother

For applying for Visa, what my wife & kids need to take along for Visa interview :-
1. Above docs
2. WIfe is working - what she needs to carry?
3. Kids - One in First Year College & other in 8th Std - what they need to carry?
4. Does my wife needs to carry Bank stt or Property Share Cert in orig & Xerox?
5. Lastly - As I won;t be inside teh consulate as have B1/B2 visa, whatall docs my wife needs to carry for her & kids Visa procssing - apart from Visa application+Payment rxpt+Passports
6. As I have B1/B2 visa, what addl doc I should carry with me when entering US as a tourist? DO I need a letterfrom my company that I am an employee & traveleing to uS on holiday or such letter etc?

Pl advise