Superboyac, I'm glad you are willing to step out of your comfort zone and try a new OS I advise you to be careful what situation you are putting yourself in. Windows has its problems, true, but Linux has its own share as well. Don't jump in expecting an easy time of it, either. Sure, things are a lot easier than they were even five years ago and there are some excellent distros out there, a lot of the problems you run into you will have to fix yourself. If you have any problem on Windows usually a quick Google search will find a blog or forum post from a Microsoft MVP laying out the steps needed to get things back on track. With Linux, while there are a lot of people out there who will be willing to help, there's unfortunately an 'ugly' segment of the population who parrot "RTFM!" and berate newbies till they leave their forums. The numbers in that 'ugly' portion of the Linux population seem to be dwindling, though, thank goodness.
Your first step is going to be to find the distro that's right for you. Everyone's got their favorites & everyone will gladly evangelize their top pick(s), but the truth of the matter is that a distro is like a pair of shoes. You have to find the one that fits you the best & is the most comfortable for you to roam around in. This step is very important, if not one of the most important decisions you'll make while in the land of Linux. Which one you choose could easily either bring you bliss or misery so choose wisely. Unfortunately, you have to make this huge decision while your knowledge is the weakest so lots of research will make things easier for you down the road.
As for software, you are (unfortunately) using two of the 800 lb. gorillas of the Windows world. The Bat! and Directory Opus do not have anything as powerful on Linux in their respective categories. The fact that the devs of these programs get barraged with requests to port them to Linux (and Mac!) attest to their power and desirability. You'll find Linux equivalents that will do a lot of what they do. You may even get lucky and find one that does most of what they do, but they stand alone. Total Commander is the only match for Directory Opus & it's Windows only as well, although lots of people report success using TC in Wine. Directory Opus, however, is too tightly integrated into the Windows framework so no such option exists for it.
While we're on the subject of software, we may as well talk about compiling. A lot of Linux software authors don't compile for every distro out there. You may be looking at a command prompt armed with source code if you are wanting to run certain programs on your distro. Are you up for that?
Linux is definitely most suited for those with a 'gearhead' mentality, those who want power & customizability and aren't afraid to get their hands dirty in order to access it. If you are more of a set it and forget it type person (the click one button or run a wizard) you may do well to stick with Windows or check into OS X.
Your OP stresses limits due to copyright. Just because the Linux guys are doing it for free doesn't mean they won't get their butts sued off as well if they violate copyright. They are limited by copyright just like the for-pay OSes are. The law is the law.
Linux can be a rich, rewarding experience, but like most things it'll only give you back what you put into it so if you are wanting an OS that just fades into the background and let's you do what you want to do be prepared to learn a LOT so you have the knowledge required to achieve that. This will not be the "drop in a DVD, click next, click next, click next, click done" Windows installation experience.
Either way, we'll be here with you every step of the way...be it to celebrate your victory over Linux as you declare your command line mastery...or...be it to cheer you on as you tie your PC's cables to your back bumper and drive down the street.