Hi Thomas, have you actually seen our capacity planning report pack in live? Basically, it provides WHAT-IF reports specifically designed to answer your questions above. You may want to request a demo with our engineer (you can do that from the product page) to make the evaluation easier for you.
Yes, absolutely - thin provisioning is taken into account.
We are working on chargeback report pack (and a few other really cool packs), they will be released later this year - I don't have specific dates for each at the moment.