I recommend you to watch some gameplays on youtube and read some reviews of the game before you buy it. Remember that NFS has changed more and more into Burnout, so you should really check if you will like the game.
I do like the game, although it has absolutely nothing to do with the best NFS ever made, which clearly was NFSMW in 2005.
To the DLCs:
- Ultimate Speed Pack seems to be worth its money, but I haven't tried it out.
- Terminal Velocity Pack is great and I can recommend it. You get a huge new area on your map and drift attack and smash & grab modes, together with the modifications.
- Movie Legends Pack: here you have to make sure that you really want to drive these new cars, otherwise this dlc will not offer anything new. I cannot recommend it, but it depends whether you are a fan of movie cars or not.
- Heroes Pack is good, but not outstanding. However, it's still worth the money in my opinion, just because of the BMW M3 GTR. (and all the other new cars are fast, too)
When you have bought the game, left click on it, press on the 'i'-button. In this menu you will be able to buy the DLCs.
I don't know what you mean with your second question. Once you have bought a DLC, it won't ever disappear on your profile because it is connected to your origin account.
