obviously, as you cannot get them w/o jailbreaking
Yes, jailbreaking does void the warranty.
"Jailbreaking" is another word hacking. Therefore you void your warranty but you get cydia, a jailbreaking software. Jailbreaking does have it advantages and Disadvantages. But if you want to send it to apple to repair it you have to restore it to factory settings to get back your warranty.
Yes; not jailbreaking it. If you mean a way to do the same thing as jailbreaking without actually doing so, there is no current way to do so.
Jailbreaking a phone is partially legal and partially illegal. I have a post regarding this http://www.techlucid.com/2013/11/is-jailbreaking-illegal-or-not/
It is impossible to get an installer on an iPod Touch without jailbreaking.
As of July 26, 2010, the U.S. Copyright Office has approved exemptions to the DMCA that permits any users of Apple devices (i.e. iPod Touch, iPhone, iPad, etc.) to Jailbreak their devices legally.Although Apple does not want you doing it and has made cases against it, jailbreaking an iPod Touch is legal. It does not violate copyright laws defined by the Digital Millennium Copyright Act.However, if you get Installous, which is a program only available for download after jailbreaking that allows you to download all applications for free, it is illegal.So, the jailbreaking in itself is legal, but using Installous after you jailbreak it to download all apps for free is illegal.However, is it 100% safe to do so? No. Many people have reported issues once jailbreaking their device, which include very slow internet service, uncooperative programs, and more.
It is up to you. No matter what you have on your ipod will become messed up when Jailbreaking...
no, it is not illegal
No
By jailbreaking it.
no