As geoffc said, it is mostly not assembled on the TEL. To elaborate, the upper rings are removed, while the lower remains. When the boosters are all connected, the second stage is connected. Afterwards, it is lifted using 4 spreader beams. (3 bottom, 1 top) Each bottom spreader beam has a attachment point for the anchors on the fuselage itself. The upper ...
When I was reading LM-3A series LV User's Manual I found this information:
In the period between T0 and T0+15 sec (for LM-3B), or T0 and T0+17
sec (for LM-3A/3BE/3C), the LV will not be destroyed by ground
command even though an anomaly occurs, unless LV explodes itself.
This is to ensure that the launch vehicle flies over 400 m (range
protection radius) ...