Iphone newbie questions/concerns?

[AprilRyan]

As a lifelong Blackberry user, I have absolutely no knowledge on the Iphone. I want to make the switch in the next day or two, but have a few questions, and was hoping an Iphone veteran can help me out:

1- If I buy an Iphone and it is not unlocked/jailbroken, is there a certain firmware the phone must be running for me to do it myself? (will be either a 3gs or 4 btw)

2- Other than receiving EDGE instead of 3g speeds, if I stick with Tmobile will there be any other features or applications that do not work correctly?

3- My Tmo contract ran out and to save a few bucks for the holidays, I switched to Tmo's prepaid plan. I have fallen in love with the price of this plan, so can I use this prepaid plan (it includes data) with the Iphone, or do I need to switch to a regular smartphone data plan? This current prepaid plan has been giving me the same 'smartphone data' on an HD2 that the 'contract smartphone data' did, so I was just curious.

4- I'd like to know what jailbreaking does in terms of apps. People say you get free apps- does that mean ALL of the apps are free, or just a few here and there?

5- For anyone who has typed on either a BB 9550/9530 or HTC HD2/HD7, can you compare typing on an Iphone vs one of those?

6- For anyone who has owned both the 3gs and 4, ASIDE from cameras/flash/screen res/design, what are the pros and cons?

7- Just how fragile is the glass? Will one drop crack it, or is it fairly durable? (I drop my phones alot and hate cases)

8- If I buy a used one off Craigslist, is there anything I must be aware of when checking it out (other than the usual call test/screen check stuff)?

Thank you to anyone who can give me some insight, feel free to add additional (constructive) info I should know as well- I really appreciate any help I can get
To responder #1-- LOL, wow. Note I said "IF" I stick with Tmobile. I stated my Tmo contract was up, so a simple 'hey, it'd really be better for you to just switch to ATT" would've sufficed. That was mainly what I was looking for.
To responder #2-- Thank you so very much for taking the time to help me out.

 

[joeeattaboy]

Let me keep this simple: buying an iPhone, trying to unlock it, then using it on T-Mobile's network is a monumental waste of money.

Think about what you're asking: T-Mobile has already deployed they're HSDPA+ network (3G+) and is rapidly deploying their 4G LTE network. They have really great devices available that can use that network, including the MyTouch 4G. Android-based phones are as good or better than anything the iPhone can do, and you have more personalization and configuration freedom with Android phones.

So, why would you spend hundreds of dollars on an iPhone just to use it at about half of its capabilities? Would you spend 100K+ on a Ferrari, then drive it very slowly around residential neighborhoods? If so, you're just showing off, and you wasting the capabilities of that vehicle. Same thing for this phone situation.

Forget all those other questions you asked. What you're proposing to do is just plain stupid. I'm not attacking you, just the idea. You're not the first one to think of this.