Not being a VSCode user myself outside of this context I may not have the best experience to answer the first question, but I don't think it tends to conflict with much except perhaps vim keybindings.

As far as using it in tandem with a keyboard, the main issues you might run into are timing. If you happen to be moving the cursor or typing while a voice command is running it could cause issues. You would probably end up having to take a second to pause and wait for the command to finish before starting to use your keyboard. Other than that, you should be able to use the VSCode instance like normal at any point.