[eluser]jalalski[/eluser]
If you've got a web hosting company that is offering unlimited this and that, then they are cutting corners somewhere, especially if they are coming at a good price. But, basically, you pay for what you get. The cheap deals are fine for most websites, with 100 visitors a day and so on. The decision is yours in the end. And, in my experience, SSH and cron are pretty much standard for most webhosts that offer some kind of root access.
For the more specific questions:
Bad indexes and long queries can be logged by MySQL which makes it pretty straight forward to track them down. What the company is trying to say, is that at the price your paying, it's not worth their time to do it. Say it takes me a couple of hours to sort out what the problem is, and I get $50/hr (so thats a $100) and you are paying me $10/month... you get the picture.
Unmetered bandwidth means throttled bandwidth. That means your pipe is throttled down so that you can't max out their lines and push them to install bigger pipes. Again, you get what you pay for.
This kind of hosting is fine for many sites. If it isn't working for you and you like the company then ask them what they can offer as an upgrade.
HTH
