What problems will happen ive overfilled the hydraulics for the roof on my 1998 slk 230

Just bring down the hydraulic level to where it should be. Use a drinking straw, place into reservoir, put your finger over top of straw, lift straw up and out of reservoir and let go into a container. This may take you a few minutes, but it will be worth not having to worry about this anymore. GOOD LUCK FRIEND.

It will most likely over flow from the reservoir, and can also over heat the fluid as it has no space to cool, but your man issue is when the fluid returns to the reservoir it has no place to go. As small as it is, I would just take a withdrawl tube and pull it down to proper level