This will be a long post.

None of us are/were American, although I'd personally love to. I am Italian and my GF was from another EU country coming here as student, yet we had problem with residency (EU citizens are under preferential regulations regarding residency, especially for students).
Unfortunately, as i told you, bureaucracy here is the real enemy. If Asti's Town Hall is used to deal with foreigners, they will have good experience and help you. Since I live in a small town, and nobody from the office was used to deal with foreign students matter, we went through a real odyssey of nonsense, wrong papers and misguidance.
For your plan you'll probably need to ask for "permesso di soggiorno" for long periods, you can get it here locally from Questura within the first 8 days from your entry, but I strongly suggest you to call the IT Consulate General in SF (definitely convenient for you) for help. They'll know what to do for sure: since you want to stay with your BF for more than 90 days, I'm not sure you're eligible for Tourist Visa. Tell them everything, and they will surely help you.
Meanwhile, you can have a look at this site for all visa types and clear your mind a little bit:
http://vistoperitalia.esteri.it/home/enOnce you'll start looking for work, things will be getting harder though. If you want to work legally, you'll be required to have a work visa, and everything I wrote you earlier becomes true. Again, the IT consulate general in SF is probably your best bet to know what to do and how.
Honestly, I wouldn't see working in restaurant or bar as a viable option at all. Working visas are expensive and are usually for skilled workers: think about it, it's like I tried to get an H-1B visa to work at pizza hut. Even if I were able to find someone so dumb to spend thousands dollars for sponsoring me as a clerk, the USCIS would probably reject my application without even looking. (forgive any consecutio temporum mistakes here

)
Italians aren't that different from Americans, after all.
Please don't consider me rude, and believe me I'm not trying to dissuade you to come here. I just think you would have better options with searching for a skilled job, but I'm probably not too comfortable with the language to sound polite. If you feel I've been rude, I do beg your pardon in advance, it wasn't my intention. If your first concern is work (and it should, I wouldn't use your 401k savings at all, really. That's your retirement, you'll need them one day), you should start looking for it right now: practice your Italian, use your BF and contacts in Asti for networking, send resumes online (ah, in Italy that's called Curriculum Vitae because we have a way with Latin, and we like it "long winded" but not so much. Google Europass CV for samples).
If you'll find work, it's very likely it'll be a little bit out from Asti, you'll need a car, and to convert your driving license, but that's life, as old Frank said. That would be a start anyways. Once you'll have your work visa, everything will change, taxes included.
I really wish you the best!

If you want to share your experience at the consulate general, I'm really curious to know it.