クリップを均等に秒数開ける

This can be done fairly quickly.

1. Open any clip in the Source Monitor and set its In point and Out point so the clip is 5 frames long.

2. If your audio is on track A1, set the source patching to track A2. See Add media to the timeline using source patching.

3. For each clip, press the Comma key ( , ) to insert the 5 frame clip, then press the Down Arrow key to move to the next edit point.

4. Repeat this until you reach the last clip.

5. Select all of the clips you added on track A2 and press Delete.

This script inserts the selected project items into the active sequence with a gap of 5 frames:
 

Just download the xml script here:
https://www.dropbox.com/scl/fi/tnagbirr810w23lqqy1vc/Insert-Selected-Clips-Into-Active-Sequence-with-Padding.xml?rlkey=4jw0m4a130a5b0cn2nj1skum8&dl=0

The you can open and run the script with my (paid) extension Automation Blocks. This also works with the free trial version.

Automation blocks may be able to do that.

​@Mathias Moehl 

I’m afraid that you’ll have to do it manually.