5) tie little tails onto the ridgeline, outside of how you're connecting the tarp to the RL, to direct water away. But this shouldn't happen much with a tarp line as it should be fairly straight, the hammock suspension will trail water a lot more.[/QUOTE]
You're right with SLS for your hammock, the line will sag. No idea how to get the proper angle other than by trial and error, or measure the angle of the attachment point to a parallel from the ground. Another thing you could do is keep a ridgeline attached to the two ends as a "guide" for your angle, this would be useful for SLS and traditional suspension.
No rule of thumb for the gap. It depends on your angle of hang. Some people hang at a higher angle, or if you use SLS you will need to anchor higher to compensate for the sag, etc. The length of the space between anchor trees will impact this as well. It's a bit of trial and error to figure out your specific setup.
Keep in mind too the load sharing quality of SLS. Not sure what your set up is, but with my SLS, I have "two" lines on each side of the hammock sharing the load (one going from hammock up to treehugger, then its coming back down to hammock before crossing over). More food for thought
Actually I've found both constrictor & klemheist to work quite well on sls.
my constrictor based sls with klemheist backups
Perhaps in the mad scramble for sexy light weightness I and everyone else has forgotten the most important function of gear – not that it must weight nothing, look good and be cheap, but that it must keep you alive and increases your survivability.