Sometimes depends if the apps that you install have bugs
Pretty much all jailbreaking your iPod touch does is give you the installer app... Which I highly recamend you do but make sure you do the write jailbreak program or it will delete all your apps music and videos and pictures
because there are a lot more ipod touch apps than the regular ipod games and apple doesnt make all the apps but they have to put more effort into the ipod games than the ipod touch/iphone apps.
some apps will make it so to access stuff on the free app you have to pay but most free apps will not charge you at all
no it wont but it might make your ipod slow
You cannot make your apps transparent. Yes you can |:/
Jailbreaking gives you access to the root level of the device meaning that software not approved by Apple can be installed. Software can then be installed that gives you access to apps from sources other than Apple's app store. Some of these are free and some you will have to pay for. Apple maintains its own app store so it can check the apps to make sure they are not performing tasks, such as accessing the user's bank account, in the background without the user's knowledge. There will be no such checks on apps from other unknown sources.
actually, you can download some apps that allow you to make calls. it might be illegal for some carriers.
A jailbreak on an iPod Touch is when a person has 'jailbroken' their iPod Touch so they can customize the lock screen slider and make chimes when they unlock their iPod Touch. It also allows the person to put apps in folders, and download something that allows you to get all apps for free (which is illegal).
Jailbreaking your iPod, can give you access to all kinds of cool things. Examples are: change your sliders, change words (like iPod on top left), change looks, cool security systems, make your apps move like in jelly car, and a whole lot more. PS if you do jailbreak your iPod, you can no longer update it, and have greater chances of getting a virus (be careful).
An ipod's Hard drive/flash memory is fixed.
no but make sure you jailbreak it to your specific ipods generation and the type of software e.g. ios 4.2