Always willing to help a member of the punk/indie community. DIY or DIE.
What is your hosting setup? Shared, VPS, EC2?
What are your settings for W3TC?
If you are on shared hosting, most likely you should just go with file cache for page and minify, and no cache for database & objects (to begin). After you get file, browser, minify settings sorted, then you can try database & object cache to see if there is any benefit. Sometimes a shared hosting environment has a slow queue for mysql databases, and it's beneficial to cache... but sometimes the mysql server is quicker than the web server.
If you are on dedicated hosting, there is a lot you can do to optimize apache and mysql to the amount of dedicated RAM on the server, and of course install APC (if you are not on Cpanel or Plesk).
The fundamentals of proper Apache and MySQL tuning are most important. The default configs for these servers are "designed to fail" under load.
Your page loads up a ton of content from lots of different syndicators, so it's difficult to tell where the big lags are occurring. But your test graph shows long TTFB and a lag on punktastic.dev.[...].ro
The first non-logged client visit is going to be the one that triggers all of the caching, so it is sometimes slow.
Non-related, are you a member of #it (indietorrents.com) ? If not, I will send you an invite if you send a message to firstname.lastname@example.org