1. No, provided that they're configured for different subnets. Particularly, don't use UPnP address assignment for both.

2. Nope.

3. Yes. It's in the network configuration dialog (just uncheck "enable autoconfiguration" for the adapters that you don't want it on. It's not a major issue, anyway, since it's designed to wait for 5 retries before responding, so generally your DHCP server will get there first.