High CPU/MySQL lagging

Hello! Im having a bit of isssue with a 2GB linode that i cant seem to wrap my head around. I have a friend's wordpress site that gets about 3k pageviews a day. it's basically a blog. I've installed supercache and all that jazz. Yet every hour or so, the server hangs. (It appears to MySQL as disabling that brings the sites online - except for a cannot connect to database error.. in other words, static stuff appears to be fine) During this time, I'm often seeing a spike in MySQL memory. Rebooting the server doesnt really do anything either - oddly. Eventually, it fixes itself and everything moves fast.

The server is running Ubuntu 10.04 LTS 32 bit, php5-fpm/fastcgi, MySQL 5.1.7, memcache

Before i stuck the friend's blog on here, CPU was sitting at a cool and constant 5-10% on my own drupal sites.

Root login is disabled (using ssh keys)

I've changed php5-fpm to ONDEMAND from DYNAMIC. I can post config files if needed too.

Oddly, php5-fpm process appears to be spikng more on average than mysql.. though i see the latter spiking too.

~~http://shion.ca/repo/linode.jpg" />

~~http://shion.ca/repo/screenshot.2015-04-24.jpg" />

~~http://shion.ca/repo/htop.jpg" />

My mess of a my.cnf file:

[client]
port        = 3306
socket        = /var/run/mysqld/mysqld.sock

[mysqld_safe]

socket        = /var/run/mysqld/mysqld.sock
nice        = 0

[mysqld]
user        = mysql
socket = /var/run/mysqld/mysqld.sock
port = 5488
basedir        = /usr
datadir = /var/lib/mysql
tmpdir        = /tmp
skip-external-locking

bind-address = 127.0.0.1

innodb_buffer_pool_size=512M
key_buffer        =32M
max_allowed_packet = 1M
thread_stack        = 128K
thread_cache_size       = 8
sort_buffer = 64K
net_buffer_length = 2K
max_connections = 75
read_rnd_buffer_size=512K

myisam-recover         = BACKUP

table_cache = 64
tmp_table_size=32M
max_heap_table_size=32M
query_cache_limit    = 32M
query_cache_size = 64M

log_error  = /var/log/mysql/error.log

log_slow_queries    = /var/log/mysql/mysql-slow.log
long_query_time = 1
log-queries-not-using-indexes=0
expire_logs_days    = 10
max_binlog_size         = 100M
set-variable = myisam_sort_buffer_size=8M
set-variable = sort_buffer=8M
set-variable = key_buffer=16M
innodb_file_per_table = 1

[mysqldump]
quick
quote-names
max_allowed_packet    = 16M

[mysql]

[isamchk]
key_buffer        = 2M

!includedir /etc/mysql/conf.d/

any help would be appreciated! Also bear with me since Im not exactly the best at all this stuff either. Thank you!~~