I don't like the VKRM of the last 1 or 2 years. Before that, they filmed much more VR with naked girls and face to face missionary. For example the title with Kinoshita Himari you mention. I bought it when it came out, and it's really good, I love Himari. I used to buy 15 or 20 titles a year from KMP, this year I only bought one.I know you don't really like VRKM cos too much clothes and so forth but you might like this one. Kinoshita Himari is a lovely girl and she's butt naked the entire video. And its just 153 yen.
I see that you have bought a lot of titles, it's normal when you start and you don't have any, they are almost for free. The same thing happened to me when I discovered the store.
When it comes to downloading, I use J Downloader 2, it goes a little faster than in the browser, and you can almost always continue if the download gets cut off. Download the files 1 by 1, if you download several at once, they all stop. Patience, it's worth it!