Can I import multiple strips of different fps into Video Sequence Editor? I have a few video strips with audio that I want to import to the Video Sequence Editor (VSE), but they are of different fps... examples are 23.97, 24, 29.97 and 30 fps. Let's say I want to select an fps of 30 in my project, is there a way to import the video clips and converting them to 30 fps?

Making every 4 frames into 5 frames, for example for 24 to 30 fps conversion. I am not sure what it's terminology in the video editing area.
There is actually an effect strip "Speed Control" which can sort of change the fps of a video strip. If converting from 24 to 30 fps, you can set the Multiply Speed to 0.8.

However there isn't any interpolation at all, it's like every 5 frames there are two frames exactly the same, thus creating a not so smooth resulting video.