It is unfortunate that you cannot produce 50p with your workflow. See how the woman on the back has four lenses, this is not because of slow shutter speed, but because of field blending. See the fascia of the roof on the back, it has coarse stairstepping and also double images. Also, converting 25i to 30p causes irregular judder. It can look better
Although if it looks good to you, that is all that matters.
I see that you are using Honestech software. I wonder can it produce true interlaced video? There are different versions, the one that I've used could only do 25p or 30p. But at least you should be able to produce 25p for youtube, the motion will look slightly better, the stutter will be more regular. Caution: 25p will likely not play on an old American DVD player if it is not a multi-region one, for it you need either 30i or 30p.
Can you share your full workflow? Do you produce 1080p files with Cyberlink? Can you do MediaInfo on the file you obtain with the Honestech?
Can you set the VCR to output PAL, set Honestech to PAL, set it to highest quality, and record 10-20 seconds and upload it somewhere, just for kicks?