If you want more general comments, rather than specific vendors, then... unless your site is entirely local/regional, then always host in the US. Always go for something that's not the cheapest, but not the most expensive. Always search WebHostingTalk.com for reviews of the company you consider.
Regarding my fear for the legalese, I suppose I need to see what kind of terms of service other startups are willing to bear and go with those until I can hire a lawyer to get proper interpretations. In any case, SoftLayer terms of service seem to give a healthy amount of rights to the customer too.
Amazon S3 can be used for most of the storage needs, but I'd need a lot of RAM for good price. Server Axis virtual servers seem good this far.
What about service-level agreements and terms of service of various providers, all I've seen would seem to leave a lot to be desired?
It's very important to have a good Linux distribution like Debian or Ubuntu where you can install/upgrade things in few seconds with apt-get.
Also it's important to have root to be able to install different apache modules, install cron jobs, be able to manage the firewalling in case of attacks (I saved myself from a DOS thanks to a Tcl script + iptables one week ago).
Virtual servers are cheap but the performance may not be bright.
p.s. I suggest to use a very low TTL for your DNS records so you can switch ASAP if there are problems. Also to try to "packetize" your application is important in order to make sure you can install without too much problems your code in a different host in little time.
Btw, you can see that I write like a child. "Scritti"? Scrivi! :-(
Btw, your Italian is fine!
Now, I still hope to get more comments on what to keep in mind when choosing the hosting.
$1,200-$1,600 for a server is not expensive. If you are trying to start up a company and you're an engineer yourself, that money is what? Your half week salary? Or we're talking about running things from a dorm room here?
You make very good point about reliability though.