You usually cannot vacuum with a skimmer sock in place because you have to take out the basket.

If your pump is what is called "uprated", it's probably OK with your filter. However, if it's what is called "full-rated" it is almost certainly too much pump and stressing or even damaging your filter.
Solutions:
1) Get a bigger filter or
2) Get a smaller pump or
3) Get a smaller impeller for the pump so it reduces the flow. If everything is good, this is the least expensive solution. The pump guys can help you with that.

Carl