Thanks Borate! Wow, that's a great method for using proxy files and I bet it would solve all my problems! NCH should post that advice on the page that lists "system requirements"! I tried to delete my post (after discovering VP automatically switches to Clip Preview) and thought I had done so since it didn't appear in the latest posts then, but I'm very grateful for the advice.
I did previously try lowering the frame rate from 30 to 15 fps, which did smooth out the operation (on this ASUS X205TA that was $200 five years ago and not at all suited to video editing!) Unfortunately, that wasn't suitable for me because for reasons I won't go into I needed to split into clips on a frame by frame basis, and when set at 15 fps the editor only displayed every second frame when I clicked "Next frame" and the splits were sometimes then off by a frame.
I did try toggling hardware acceleration off, and that may have helped though I'm not certain.
DirectX is supposedly 11.2 for Windows 8.1, which is updated, but dxdiag seems to report "11" in one place and "11.0" in another; I don't know how to update it further, but I doubt that's the problem, and this laptop doesn't have a video card.
I had numerous confusing problems such as the time bar jumping around, which I strongly suspect were due to the laptop being underpowered. Perhaps the software then can't keep everything in order; just patiently waiting works sometimes and not others. Other problems were more mysterious. For example, on launching the program I started getting the error message: "Error loading files There was an error loading one or more of the effect or transition icons. Please reinstall VideoPad to fix this problem. If the problem persists, contact NCH Software support at http://www.nch.com.au/support/index.html" Using the Control Panel to uninstall/change brought up an NCH module with a "reinstall" option which I chose, but I still got the same error message on opening VP. So then I deleted VP entirely and reinstalled from scratch, and that fixed that problem.
Other things were confusing for a newbie because things would work one time and not the next, presumably because I didn't go slowly enough for my laptop, and I found the instructions for applying effects were not detailed step-by-step enough for me so I was guessing. Found I could use Google to search site:nchsoftware.com since the site itself had no search box, just a table of contents. Had to use the undo button a lot, and start from a previously saved version of the project file a lot. By trial and error I think I've developed a work pattern that will suffice. For example, usually I can find the place I need to apply the Effect using the large red time position slider in the Sequence preview, note the exact time, select the clip, select Video Effects, VP then switches to Clip Preview and I can go from there...but if Clip Preview automatically opens in a different (wrong) clip, which seems quite often, then I can use the small red time position slider in the Clip Preview to get to the right clip using the time I previously noted being careful since that timeline doesn't expand (would be problematic on a long video).
It seems great software though a bit short on the documentation for a beginner, and the video tutorials were mostly not helpful. I was a little surprised that effects could not be applied to random portions of the video rather than just to demarcated clips.
Thanks again