Q1. Could I extend my J1 visa after waiving 2 years rule? Q2. Could I extend my J1 vias under pending waive the rule?
It depends on your agency to extend your J-1 program. Please check your agent.
Q3. What if I enter USA with tour visa(B1) after J1 expired ? It could be a problem when I apply H1B ?
Somtimes, B-1/B-2 visa is an option to enter into the United States. However, you cannot work with a B-1/B-2 visa. As long as your keep your status legally, you are not going to have any problem.
Q4. If I change my visa status to F1 here ( may be a community college ), could I apply H1B without problem?
That is also an option. Some people apply for F-1 visa and reapply for a H-1B visa when it is available. As long as your F-1 application is approved, you can change your status later.
Q5. Could you recommend the best way I could stay here and get H1B. ?
It depends on case by case. I cannot say anything without any personal and financial information about you.