I don't think it has Securom at all on it. I did a protectionid scan and it's just a simple check.
I strongly recommend getting the first one, these games are all about YOUR choices and how they play out for your particualr playthrough. The default "canon" choices made for your character when you create a new one in ME2 are pretty crap for me at least :p
You see you have even minor encounters and side missions count in the sequel (even though many of it only gets you a new message in your mailbox), so if you helped someone out you might like to see the consequences in the second just saying.
If all fails you can also look into this site and download a save with your preferences to import it into ME2. But you should really experience it for yourself.
ME1 and ME2 are two different games alltogether, and ME1 is still my favourite among the two. You have some RPG elements in ME1 (mods you can install in weapons, many many different types of guns that start to look the same after a while...) + character attributes settings you would expect in a role playing game. The combat is run and gun with cover system and a command system (you can tell your squad to move, take cover and attack). Depending on your class and the people you take with you, you have can pick from many different defense/attack abilities that make some battles incredibly fun, but that's just my opinion.
The whole system has been stripped down to its bare bones in ME2, you now have so called "missions" at the end of which you get your stats on how succesful you were (experience points gained, abilities unlocked, credits gained). The combat has gotten a complete revamp, it plays out more like gears of wars or something. Your companions now have like 2 special abilities and can only choose between two weapons, a real 3rd person shooter.
Enough of the small rant, the character interaction is brilliant as is your own character development throughout the game which is the whole point of the game I guess since teh main story arch doesn't move much at all if you think about it.
So, just saying that they are very different in term of atmosphere, gameplay, story development. You might want to find out for yourself how you feel about these changes if you play both. But right now the only place I would recommend getting ME1 is STEAM, it has the Securom removed there (but STEAM api remains).
ME2 has only a disc check as has already been said, for DLCs you have one time activations then you can just go into offline mode again until you get a new DLC or reinstall the game with the DLCs!
Zaeed and Kasumi files were already in the retail version, and you could get them by cheating in the final mission (in the rest of the games if you select them you would only get you other companion in your squad). But that's only a case of facilitating the deployment of the DLCs for later on (so that it would not broke the whole game and actually work) which were onviously not finished at that point. The Zaeed content was most likely not done when the game reached the gold status (and the big game companies prefer to make some bucks as soon as possible!) after that you can't change anything anymore even though it's still two+ weeks until the official release date.