When you get those littler hitch hikers on your LR do they survive the cycle?
Usually. The common hitch hikers wont have a problem, but sometimes you can get fragile organisms on there that will perish.
I know LR removes ammonia and nitrite but does it remove nitrate?
In theory, yes, in practice, sometimes no. It all depends on how long your LR was left out of a curing tank and without a food source... Alas, there is no real set formula.
What would be the benfits of having 30 pounds of LR in the main 30 gal aquarium with the fish and corals and 30 pounds in the 30 gal sump? (so basically 60 pounds of LR over 60 gallons of water filtering the waste capacity of a 30 gallon tank)
More filtration capacity and more area and possibility of being able to process nitrates more effectively. Basically makes the tank less of a worry from a nitrogen cycle standpoint. It also provides a great way to colonize and grow copepods which is a natural food source for many reef fish.
Is there any clear difference in performance of LR and LS?
Complicated answer here. IMO, LS is a waste of money. Sand becomes live very quickly (within a month or two) when LR is present in the tank. So I tend to advocate spending money on LR as opposed to LS. Shallow sand beds 2" or less in thickness will not harbor dentrivores that process nitrate. Deep sand beds (DSB) of 4" or greater will process nitrates if given a very long time for the anaerobic bacteria to grow there. The downside to DSB's in the display tank are twofold. #1, they take up a lot of viewing space. #2, they can harbor pockets of cyanide which if disturbed will of course kill your livestock. For these two reasons, especially #2, most people who choose to use a DSB have theirs in their sump, not in their display tank
Why is live sand so much more expensive per pound?
I'm not really sure there...
Im still a bit confused about coralline algae, could someone explain it?
Sure, its an algae type that grows in reefs. It requires calcium, light for photosynthesis, and nitrates for growth. Its basically a plant that grows its shell out of calcium. It looks really pretty (usually purple colors) and can process nitrates. Given enough time it will cover many surfaces of your tank including glass and plastic.
