My hammock is 11' long. Does this mean I need a 12' ridgeline tarp to make sure I'm covered?
If you have an 11' hammock, you have about 109" of hammock within the 11' ridgeline, and with the tarp at 132" of coverage, that leave you with 11.5" on either side of coverage, so you should be fine with a 11' tarp. We recommend 11' for most folks because to find trees that will work with 12' tarps can be trickier. That being said, plenty of folks order the 12' and make it work. If you are in a heavily wooded area, then you would have more choice locations to fit that length in, but it is a preference.
I have a bridge hammock. How do I make sure I have enough clearance so my poles do not puncture the tarp?
Bridge hammocks are becominng very popular. To compensate for the extra space needed to clear the poles, you can request that the panel pullouts be spaced in the proximity of where the poles would be, so you can pull the tarp panel out further to avoid contact and possibly puncturing your shelter. The pullouts, generally 49.5" apart, can be modified to 77" apart to create the recommended spacing for clearance.