Is this amount of disk IO expected with MySQL?
MySQL Disk USage
SELECT IFNULL(B.engine,'Total') &quot;Storage Engine&quot;, CONCAT(LPAD(REPLACE(FORMAT(
B.DSize/POWER(1024,pw),3),',',''),17,' '),' ',SUBSTR(' KMGTP',pw+1,1),'B') &quot;Data Size&quot;,
CONCAT(LPAD(REPLACE(FORMAT(B.ISize/POWER(1024,pw),3),',',''),17,' '),' ',
SUBSTR(' KMGTP',pw+1,1),'B') &quot;Index Size&quot;,CONCAT(LPAD(REPLACE(FORMAT(B.TSize/
POWER(1024,pw),3),',',''),17,' '),' ',SUBSTR(' KMGTP',pw+1,1),'B') &quot;Table Size&quot;
FROM (SELECT engine,SUM(data_length) DSize,
SUM(index_length) ISize,SUM(data_length+index_length) TSize FROM information_schema.tables
WHERE table_schema NOT IN ('mysql','information_schema','performance_schema') AND
engine IS NOT NULL GROUP BY engine WITH ROLLUP) B,(SELECT 2 pw) A ORDER BY TSize;

This will tell you exactly how much diskspace (in GB) MySQL is actually using for tables.
Please see my other post CPU usage on RDS instance monotonically increasing with no change to query volume on additional Storage Engine diskspace queries.
You also need to do this
cd /var/lib/mysql
df -h .
ls -l

Take note of ibdata1, ib_logfile0, ib_logfile1, and other files. You will also see how much disk is free for the disk holding /var/lib/mysql
Please run ls -l /var/log/mysqld.log to see if the log is too big.
MySQL Memory Usage
You have
innodb_buffer_pool_size=64M
query_cache_size=64M
key_buffer_size=64M

That's 192MB. Since you have a lot of other defaults, you only have about 100 or 131 max connections. I recommend downloading MySQL Administrator for Free and watching memory usage in other aspects.
Epilogue
Please look over my Amazon RDS posts for other ideas

Should I increase max_connections in AWS RDS t1-micro for MySQL?
When should I think about upgrading our RDS MySQL instance based on memory usage?