- You need a license for every device you manage. If not included with your hardware you need to buy it from your software reseller.
- DS is perfect but only free for the evaluation period. You buy Ds with a license for xxx clients. Clients do not store the license, this is managed at the server level. You should take extended maintenance for futurue updates (some are on their way I think I can add safely) and support. When you are going out of license, DS tells you and you have a grace period. You can buy additional licences and add them.
Some advice (not asked for but never the less): it is a great product. You can learn it on your own but that will take a lot of time and effort. Going into class for 5 days DOES PAY OFF!!!! Also some consultancy would not hurt.
Hope it helped
Good luck and enjoy DS!!!