Congratulations Vibor! I'm so excited for you!!! I know you have been using a Bosto and am really curious as to the differences? Give the White felt nib a try. Its my favorite!
As for the screen protector. No. One of the niceities about the cintiq is the screen texture so I wouldn't do a screen protector. Its like buying a pink iphone and covering it with a big ugly OtterBox. Lol.
You WILL damage the screen over time and wear out the texture on it but I have been able to keep all six of my cintiqs in great condition taking a few precautions:
1.ALWAYS use protection! No glove no love. Everytime I draw, I always use a cotton glove. Whatever fingers you use to hold the pen cut them off (because just like a good rubber, you want to have a bit of feeling). Even short uses with no glove, I'll make sure my palm is hovering over the tablet.
The reason you should do this is that the thing that ruins the screen is the oils in your hands and not the nib of the pen. The oils in your hands deposit on the screen and when they dry they create an invisible micro crust. When you drag your pen over the crust, it will turn into an abrasive. Its like a car's finish. When you rub your hand across the car body, its not your hand that scratches the paint, its the dust that you're rubbing around.
2. The glove won't protect all of the oils from your screen so clean your screen once in a while with a screen cleaner. Spray, spread around, let it soak a few seconds, then wipe it off. Replace your nibs or just pinch them once in a while to get any grit or dust off them too. Sometimes, the nib collects a bunch of dust.
3. The eraser does not have a replaceable nib so you have to set the sensitivity on high so you are not tempted to press too hard. The hard plastic can wear out quite quickly (like a nib) so if you press too hard you will wear a flat spot that could scratch your screen pretty quick! I once in a while spin the eraser a few degrees to make it wear evenly but that's just me!
4. My Cintiq was in a dusty environment once and I just put a towel over when not in use. If that's a hassle, just keep a microfibre duster close by and make it a habit to give it a quick dusting before you use it.
5. Cuff buttons, bracelets, watches, long hanging chains, coffee cups, mobile phones, metal rulers... all dangerous around cintiqs. Once your screen is gouged, it will be years of frustration!
The only screen I ruined was my Cintiq Companion (Wacom replaced the unit for me) and because it was a touch screen too and there is no way to keep oils from getting on the screen (its the reason why the only touch cintiqs come with cleaning cloths). I would turn the function off completely or clean well before every drawing session.