1. When you purchase the software, you can export the code to put it on your own server which I'll assume you have a website host already right? If so you don't have to do any Database stuff at all, it's all taken care of as long as your hosting company has setup your account with PHP of the required version (check here for what is required: http://www.coffeecup.com/help/articles/ … m-builder/
If your server has the correct PHP setup, then you don't need to worry about anything at all with databases unless you really need that as the form is pretty self sufficient and takes care of all the server stuff for you. In other words, you put the code it gives you on the page, you upload the files it tells you to (make sure to read it carefully and not upload the folder with the _exported at the end of the name, upload the files "inside" that folder). That's all there is to it.
2. You can continue to use S-Drive for as long as you want if you don't want to do your form on your own server. Fees are setup according to your plan so you'll have to check your S-Drive plan to know how many times your form can be used when it's hosted on S-Drive. When you host it on your own server there are no limitations.
Width of the form can be set in the Form Builder itself on the last tab "Form Options". There you can tell it how wide you want the form to be. Height will usually go with however your form is setup and will pretty much set itself up for you once you have all your elements in place where you want them. Play with the width percentages of the elements as well as the padding of the elements to get them placed exactly how you want them. You shouldn't "have" to edit any of the sizing outside of the program, but you can do so if you choose to.
The setup on S-Drive will work exactly as it does now on the free version, you'll just have the ability to export the form to use on your own server, that's really the only main advantage to the software purchase, but the help on the forums is quite worth the price too.
Hope that covers most of what you were asking, if I've missed something, can you explain a little differently so I can understand what you're needing to know? Thanks and good luck!
