There is no way to control your iPod Touch from your computer without jailbreaking. Even if you were jailbroken though, I don't believe there are any modern packages that could help you.
no you need a computer to do so
yes you can just go to cydia and download mewseek if jailbroken
no
Cydia is an app itself you get when you jailbreak your iPod touch. You get it when jaibreak is finished, if you have greenp0ison, you have to go on loader and download Cydia from there. If you use redsn0w, you will have the choice of downloading Cydia from your computer to your iPod.
you get cydia by going to cydia download ipod touch thanks ]
Cydia costs $9.99 on iPod touch.
Restore with backup
I don't now a other way to get cydia of but the only way I know how to take cydia of is to restore your iPod touch
No
You can get an installer without Jailbreaking it, using a program called 'Pusher'.
There is no way to install Cydia without jailbreaking.
Cydia itself is considered to be safe but apps that you may download via Cydia will not have been checked (as they are from Apple's App Store) and so may compromise your personal information without your knowledge.