Currently those two live path effects create crazy things when used with grouped objects, it's probably because they are applied to each object in group seperatly. I know that this is currently worked on, but Is there any temporary workaround for this? Like applying multiple filters to the same object - such option is currently not available, but it can be done by putting object in group and applying filter to it.

i do believe the current development versions allow you to apply live effects to groups, but not the stable version.