DB2 for RTC standard edition

Hi,

We are using RTC 2.x Standard Edition, with DB2 9.5 FixPack 5 Workgroup Server Edition.
At RTC 3.0 download site, I found that we can use DB2 WSE or ESE.
from our PA site, we downloaded DB2 ESE.

9.7 Enterprise Bundled for 64-bit platforms and 32-bit Windows
9.7 Workgroup Bundled for 32-bit Linux.

As a customer of RTC standard edition, I want to ask:

1) Can we use DB2 9.7 ESE or continue using 9.5 WSE FixPack 5 ?
2) If we can use DB2 9.7 ESE, must we migrate our data from WSE to ESE edition (even this step is needed in upgrade process from RTC 2.x to RTC 3.0)?
3) For RTC Standard Edition Customers, is 9.7 WSE available ony for linux?

Regards,