lz,I did that kind of transfers many times. My credit score is not bad so almost everytime I could get an new card before the 0% ends and then transferred the debt to the new one. Yeah, you may not transfer to the same company's new card, but you can always deposit the check they mail to you and pay the old debt by those $$. good luck~~ 

Are u saying even i cannot balance transfer between cards owed by the same company but if I do check deposite, i should be fine. am i right?

Yes, usually after you open an new credit card account, the credit card company will send you couple checks for deposit or to pay high rate credit card bal. You can make those checks to yourself and deposit into your check account（make sure dont go over the credit line of the new card though and do read the fine prints on the letter which comes with the checks). After the $$ is credit into your checking, you are free to do anything with those $$ including paying off the old debt carried on the same company's credit card. And the $$ amount you deposit will appear on your new card and bear the new APR.

for the 12 months 0% on bt, does it starts from your 1st time using the card, or the application approved?

Did you mean when the 0% starts? It depends. Again, fine prints are really important to read. There is detail information about that on the application. Usually 0% starts to apply to the transferred bal of the 1st billing statement, and lasts for 12 statements. And be careful, if the 0% APR is only apply to bal. transfer but not purchase, then everytime your monthly payment will apply to the lower APR, which means that your purchase bal. will be subject to the regular APR.
  

if i get a card w/ certain amount of credit line, which is not enough for $$ i need for BT, how much possibility i can ask to increase the line to the amount i need? does that need to go through the credit review as well? i never increased credit line, only decreased it b4. so, not sure about the process.

From my experience, I almost could always increased my credit line after I opened the account. I am not really sure about if they still need to go through the credit review b/c some of them increased my credit line right away during the phone call I made to request the increasing, but some would say, ok, we got your request and will made the decision later... So I guess it really depends how your credit score is, how much outstanding debts you have, etc.
  

thanks for input