1. Just build your VSA with "VM Network" as VMware said and later on (when VSA will be in place already) add your different production networks for VMs. However, you should be carefull with VLANs, so if you have enough NICs I would recomend you to create new switch just for your VM networks (or you can add it to your first vSwicth, but dedicate separate vminc).
2. You can easily change your VMotion network to "VSA-VMotion". However, based on my experiense VSA build process sometimes fails with preconfigured "VSA-VMotion" network. The workaround is to use "VSA-VMotion" with DHCP and let VSA to configure everything during the installation, and after VSA installed you can change settings on "VSA-VMotion" to whatever you want (like non-routable subnet).