I can ride no hands and do so as part of pedaling drills. No hands pedaling requires one to steer the bike with the core muscles. I do it sometimes riding uphill to make it tougher. The best way to look behind is to rotate your head and touch your chin to your shoulder without rotating your shoulders. Use the peripheral vision to look behind. Several of my track racing buddies who are late 60s and early 70s, ride no hands at the track and do not have a problem looking behind.