First, the site has been up and running. I've apparently been hacked three times, and each time I used Akeeba Backup to roll back a couple of days, which seemed to resolve the problem. I did that again this morning.
I downloaded and installed Akeeba Admin Tools Pro today. I went through the setup wizard step by step, very carefully. As soon as I clicked the Save & Close button, I went back to my site and got this message:
"Your host needs to use PHP 5.3.10 or higher to run this version of Joomla!"
Read the troubleshooter, and decided disabling Admin Tools by renaming the main.php file to main_disable.php. This had no effect.
I decided to simply restore the entire site, which I have done in the past using Kickstart. I uploaded Kickstart and restored the backup from two days ago (the same one I restored this morning), and as soon as that file restored and the Cleanup button appeared, another tab opened and I see the message:
"Akeeba Next Generation Installer For Joomla! requires PHP 5.3 or later"
I think since this program has run in the past and I don't believe the PHP version would have changed to an earlier version, I'm running into another problem, but I have no idea what. My site is down, although I can get into the host administration stuff.
I did nothing with htaccess, as every time I've touched that in the past my site has been unusable. Unless the installation wizard did something with it, I don't think that's the problem.
I'll try to confirm exactly what versions I'm running.