The casts/hour is about 600-700, about 260 crims/1k bursts, total summoning xp/1k bursts around 100-110k depending on level, mage xp ~190-200k/1k bursts. This is all my data, it may be a little different for you. If you have any other charms, save the blues till at least 79 or preferably 89, and use all the other charms BEFORE crimsons. You're indeed best off using your crims on granite lobsters until you can make swamp titans. You can use around 3k charms/hour with the kyatt, so the xp/hour rate is quite high (~250k xp/hour with golds) to completely awesome (like 2.4m xp/hour with blues :P). I'd just trade in the pouches, not really worth the extra time making the scrolls.