Vertexx: The pricing on the Ring of Sequestering is less about being able to have greater invisibility, and more to have a form of invisibility that cannot be detected by see invis or true seeing, a magical feature that can only be duplicated by mindblank, a 9th level spell. Considering that true seeing and see invis are extremely common at this level, this feature of the ring of sequestering is what justifies the cost.
You don't need to roll initiative, since technically the series of readied actions that take place sets the initiative order. If someone else joins in then initiative will be rolled.
Prontius doesn't really know how practical a grapple will be, though he does know there are alot of defenses against such tactics.
Shayuri: Hate to lose you. Sorry it didn't work out.