When you do the JS1, set up your desktop so you can easily see the questions, while still looking at the camera to maintain eye contact. If something catches you completely off-guard, take a deep breath, say "let me think about that," pause, and glance over your notes and see what you have to work with. Pausing for a second is absolutely no big deal and looks better than rambling. Although, I verrry much did the latter for one of the questions and I still got in, so don't stress too much if it happens.
This is great advice. It's always better to take a pause before answering any question you're even a little stumped by. It is no problem, and in fact looks like you're thinking and trying to give a thoughtful and well considered answer. They are asking you big questions, it would only be natural to want to think a tick or few before giving your response.