Fact or Fiction--Trailer tie downs
The problem with the shock discussion is the coilovers aren't meant to take that cycling, and produce lots of heat, which breaks down the oil or causes leaky shocks. Saying that, you only really have to worry about that if you have a leaf sprung trailer. The torsion type trailer axles are much smoother and easier on the car's chassis. I would just check how warm the shock is, but be careful you could burn your hand.
As for tying my car down, I do the same on the axle and K member. I usually use the lower control arms, but I find they are hard to gets tie downs around with everything around them. I also cross the straps to keep the car from shifting from side to side.