I had my first Zwift 'crash' yesterday when I was sucking onto the wheel of a small group, and another rider came up from behind and muscled his way in front of me. We both veered right off the road suddenly and I had to sprint to catch the group.

I still have trouble catching and maintaining the draft of another rider or group. I am going to try the front handlebar view to see if it helps me judge the distance.
On a side note I rode portions of the actual course in Richmond this past weekend (albeit on the 29er MTB) including Libby Hill and 23rd St climbs. Fun!