I'll admit I'm not used to doing readings and recordings like this at all. First time I've ever really recorded and listened back to my voice. Because of that, it probably sounds a bit more unnatural than my normal speech. Some of the weird accent quirks you identified may have come from my first learning Japanese in Kansai, speaking with people native to that region. Later, when I lived in Tokyo, I tried to conform to the 標準語 style, but I'm often told that my accent/intonation is more Kansai-sounding on certain words. I could totally hear it popping up again with "おんな" in my reading.
Could be it! Though frankly I have no idea, I only know that the pitch accent is different in Kansai.
Did you take speech classes at all? Also, what NHK pronunciation dictionary are you referring to? That might be interesting to look at (although I don't know if I necessarily want to sound like a news caster).
We had speech classes of sorts in my curriculum. That's how I was first acquainted with the notion of pitch accent and realized how horrible my accent was. My teacher would make us repeat our replies over and over so that we would properly rise and fall correctly when speaking. Being a sucker for this kind of things I paid special attention during those exercises when others just couldn't wrap their minds around it (which is fine, if anything you don't need it to make yourself clear in Japanese).
The NHK publishes this dictionary where all the hyoujungo pitch accents for all the words are indicated. On their own, they won't make you speak like a newscaster. They'll just help you having a more natural hyoujungo word intonation. My denshijisho comes with it, that's how I got it. I don't know if there are more complete versions (teaching how to actually speak like a news caster), but the one I have is only comprised of pitch accents. No definitions, no sentence intonation, just word-by-word pitch accents.
The rest is just me trying to listen and practice. It's still far from perfect, and the text I read is a best case scenario. My 'spontaneous' Japanese doesn't sound nearly as natural (though I'm trying) as that thing I read.
Anyway, it might be fun to do another take with some completely different material. Any suggestions? Something more casual/colloquial (like text from a manga, for example) might be cool.
I was thinking that too. Anime/manga/drama, or just casual conversation stuff. There's nothing that comes to mind right now, but if you think of something just suggest away (or better yet, do a take and challenge me and other people here to do better ). If I have an idea I'll share.