If I may pop in on this, over the past few years I went through the same process [trying lower Keyframe Intervals (which looks somewhat worse if you go too low, in most codecs) to help video editing] and eventually just tried switching from the higher-end NLEs (Premiere/Vegas/etc) to the more mid-range ("Prosumer") level video editors - finding that these actually seemed to handle larger Keyframe Intervals and even VFR material, with less issues.
My suggestion then, would be to try products in the realm of Cyberlink's PowerDirector or Corel's VideoStudio and similarly-priced products (I haven't tried any MAGIX products yet; but I want to in the future, especially now that they bought Sony's video editing line) - with these editors, you may not even need to worry about 'converting for editing' at all!
[Note: I am not affiliated with these video editing products or their companies in any way or form, I have merely been a user of their products over the years and wanted to share information on the capabilities of these products that may be of some assistance]
Try out some Demos and see how the most recent versions work for you. Have fun with it!