a) They're not on *my* recommended list. I've heard very few good things about those hosts. I am not part of wordpress.org, I basically just moderate the spam on here (for free, mind you), and help out when I can. So don't go thinking that there's some keen master organization here or something, because there really is not.
b) I have no idea what "GPU" is. You keep using that term, but it has no meaning to me. I've got dozens of sites on several hosts, and I've never heard of that term, nor have I had any speed issues on any of them.
c) If 2.7 isn't working out, then roll back to 2.6. Or switch to another platform. Maybe WordPress just isn't right for you.
But if you want to actually try and solve the problem, then I'll be glad to offer you advice and thoughts and ideas... but that's all I can offer you. I'm not really interested in anything other than talking technical details.
You say you're getting all these hits to your site... From where? Have you looked at the actual logs? I mean, you're basically just giving numbers, but those aren't enough to debug a problem. Where are the hits coming from? If you only have 3500 page views, why is index.php being hit 15000 times? What's hitting it? (note that with WordPress, *all* hits for any page will be to index.php, as it handles rewriting internally.) What, exactly, is hitting the wp-cron.php file? What's the contents of the cron option's value in the database? These things are important to debug just what's going on. Turning stuff on and off at random isn't going to solve your problem or give anybody any useful information with which to fix it.
If I'm removing as much of the optional stuff as I can and the problem persists, then it seems to me the problem is with the core.
Wrong. That tells you that the problem is with your *server*, in some way. Why? Because the problem does not manifest with WordPress on other servers. See, if it was a core problem, then everybody would have it. Right? I mean, I can setup WordPress on my own boxes and it runs fast, without any speed issues and without hitting any processor problems. So, why is it happening on your box and not mine? That's the question. What is the difference on your hosting systems?
Also note that the WordPress 2.7 codebase is running WordPress.com as well, which hosts a few million blogs, and has something like a billion hits a day (what with them also hosting major sites like ESPN and CNN and so forth). Admittedly, they have a much bigger setup, but still, if there's any speed issues, they find them pretty fast that way, as they push the latest WordPress code to that system something like 10 times a day.