Can sims 2 clothes bee converted in blender? how hard is it to do, and what adjustments are needed from normal meshing?

You really dont want to go there
Adjustments:

Renaming all the joints.
Fixing the arm position.
ReUVmappin the outfit and skinparts(hands/feet/neck etc)
Fixing the faces on neck/waist/ankle.
Fixing the normals on neck/waist/ankle.
Making morphs.

You best use sims 3 hands anyway as sims 2 hands are diffrent.

thats a lot more than i expected O.O thanks anyway!

I did TS2 to TS3 body conversions for my Servo and Skeleto sims, but they were 'easier' because their bodies are just 'sticks' and don't require muscles or morphs, and even that was tedious enough that I'm (probably) never going to do it again - but reassigning all the joints for regular clothing plus repositioning the TS2 mesh arms to the position needed for TS3 arms, and then having to make morphs, is a whole new world of pain (I've tried!) and as Bloomsbase says, you don't want to go there!

The best thing to do is to find a TS3 mesh that's as near as possible to what you want to make, and reshape the mesh using the TS2 mesh as a guide. Then use the TS2 textures as a reference pic for your TS3 textures (or if the TS2 textures are high res enough, you can painstakingly copy and paste each body part onto a TS3 texture (you have to do it part by part, because the location of each of the body parts on the texture map is different in TS2 from TS3). Still quite a bit of work, but a lot easier than doing an actual conversion!

If you have Milkshape i can save you some work.
I once made a file to convert all the joint names and a small tut on how to fix the arms:
http://www.modthesims.info/showthread.php?t=407561

dont worry, a friend of mines emailed me a link to the clothes already converted XD unfortunately milkshape doesnt like my laptop