Hi @kirkbcb,
Some of the issues you are facing could look like known bugs fixed in version 3.0.3, see the release notes for more details:
http://docs.couchbase.com/admin/admin/rel-notes/rel-notes3.0.html
But the errors you describe could also happen if you are running low on resources in the cluster nodes. From what I can read here: http://aws.amazon.com/ec2/pricing/
Each node has 8 cores, 30GB RAM and 2 x 80 SSD.
Cores and RAM seem okay, but how mush free disk space do you have on each node?