The mast should be sealed. All catamaran masts should be sealed. If not, you can seal it youself with a nice bedding compound (NOT 3M 5200!).

Doubt you'll need a righting bag for the 450. Purposely capsize it near the beach with an onshore breeze and try righting it a couple times. You can also capsize it in waiste-deep water and have someone hold the bow to keep the boat from drifting around while you try righting it.