So I go back to the installer and try it again after working with host support and it works. Well mostly. I see the db config save without error, the db insert messages go by within about a second, and then I get an InvalidArgumentException.
Nice dog. That decision is out of my hands. I'm the new guy on the block with the owner of the domain and with web dev in general, so it's premature for me to suggest that. And I am learning a huge amount from the trouble. What I would have learned if the install had worked the first time is relatively little.
I do hear the suggestion and am considering going to HostGator where I was able to get a better domain name. I did go there and tried to set the domain to point to a second domain (which will host xf) and was not able to do so. Same feel as the trouble with current host. They try to funnel you into more purchases.
I will admit there's a lot I don't know, but I'm certainly capable of learning and I am. I see these as technical issues and so far all have been solved with some time, careful attention and support from xf and our host. I'm aware of how fast it could go, but I'm not giving up here.
I redid the install, complete from download on and it worked. Only difference is I used a directory called 'Community' instead of 'Forum'.
Other details: Downloaded fresh zip, unzipped on windows box, deleted old directory 'Forum' on host, created new dir 'Community', used WinSCP to copy contents of upload dir on C drive to Community dir on host. Reran install. This time the database inserts took about 10 minutes, but everything completed in a timely manner. Good file check from admin page.
Next step is to set up a few forums and try to get a second domain to point to it from HostGator.
I'm not done with the concept of finding a new host. Not by a long shot. I've purchased a better domain name from HostGator (they were sitting on it) and tried to point it to our current domain with no success. The named server setup did not work. I have yet to contact them about this and will do so now that the forum is installed. We'll see how that goes. They want to sell hosting, for sure. Since this new domain is a better name we may very well end up over there for the forum and keep DreamHost for the current .com.