It loaded on the webpage in about 3 seconds for me. Is it slow for you in Tableau Public application? Public website, or both?
Also the tooltips seemed to work. The text spacing looked a little weird on some of them but I wonder if that is the data. Which browser are you running? I'm Firefox vs. 44.
I understand your gripe here, as I struggle with the same thing on Tableau Public. It's a really nice-looking viz, but truly instantaneous tooltips are exactly what it needs to make the details conveniently accessible. Users shouldn't have to stop the mouse on every block to see the tip.
My only solution so far has been to abandon Tableau and work with D3 instead. I have a conceptually similar viz using D3 on my blog, but I have to warn you, it took a long time to teach myself how to make it: David Waldron's blog: What kind of work experience do you need to be appointed to the US Supreme Court?