I finished the storymode without a single problem and create mode works perfect.
The only bug i have is that in the goodies bag some materials from lbp2 and lbp1 appear like that warning sign that you get when you place too many things together but they work correctly when using them so its not an actual problem for me

I have this bug too. This will likely get patched in the upcoming update, I only don't know when that update is going to be released.

On the other hand, if you're too impatient, you can try the following:
- Back up your profile and every level
- Delete the WHOLE game
- After that re-install the game
- Import profile

another problem i have is the infinite loading screen, but i already had it back in lbp2

I'm a missing a few things from LBP2 and I literally cannot get online due to time out errors and other errors... Also, is the grabinator and hook claw thing from LBP2 meant to be in the goodies bag as it's not there for me?

I've not had a single problem either

Try playing with people online. That's total H-E-double-hockey-sticks.