are these needed?

I wouldn't say any of those are needed, I never had any of them. I never saw most of the issues those say they fix, so I don't know if EA fixed them or I just missed them.

But, there are some things there that you might like in your game, so I don't see why you can't give them a try. Both MTS and moreawesome have a lot of great things, and they are the only two sites I ever downloaded CC from. I did have quite a lot in general. But most of mine was recolors, custom skins, eyes, etc. and a few behavior mods to fix things that annoyed me.
I would just say, carefully read descriptions and read at least a few of the comments before you decide what to add.

Lord Darcy created a lot of fixes for TS2 until the games were patched. No, most of these are not needed. K&B was patched up shortly after release back then. It wasn't created by the team at Emeryville or Redwood, but a different team no on site, and left out many of the bhavs it should have gotten like would include all the other packs' options. It was patched about a month later. However, on MoreAwesome Than You, where most of Lord Darcy's stuff was also listed, you may want the one that allows Sims (or place objects) to walk under modular stairs etc. Some of those are extra benefits, like that particular mod that Maxis never did add to the game. Those type of things are enhancement mods.

But no you don't need any of them, I don't have any of these installed once the packs were patched. Unless there is some extra enhancement mod I would want.