DRA821U-Q1: Which part number is available ?

Tool/software:

I planned to build B samples 

1. DRA821U2EGBALMRQ1 100pcs
2. DRA821U2E5BALMRQ1 20pcs 

TI Supporter pointed out 1. is not available, so he recommended DRA821U4TCBALMRQ1 to replace 1.

Q1: how can we lower the clock rate from 2GHz to 1GHz?

Q2: how much power consumption difference between DRA821U4TCBALMRQ1 and DRA821U2EGBALMRQ1 even we lower the first one to 1GHz?

Q3: do you think all validation on DRA821U4TCBALMRQ1 can be carried over to DRA821U2EGBALMRQ1 ? as you know B sample will be used by our board level validation and also customer vehicle level validation, the effort is huge if we need to repeat the test.

Q4: do you have speed -C devices available for both security and non-security ? we want to have same speed rate for both security and non-security.

Q5:you have other better suggestion? 

Thanks

Max