Thanks, that's great support!
Regarding the CHMOD issue, here's what WP says:
Some plugins require the /wp-content/ folder be made writeable, but in such cases they will let you know during installation. In some cases, this may require assigning 755 permissions or higher (e.g. 777 on some hosts). The same is true for /wp-content/cache/ and maybe /wp-content/uploads/
Additional directories under /wp-content/ should be documented by whatever plugin / theme requires them. Permissions will vary.
So I think your judgment is best on what to do here.
One other thing I noticed (but haven't checked lately): With an Installatron installation, the site and blog URL in WP seems to default to:http://domain.com/directory
...without the "www".
I prefer the "www", and when I do a manual WP install and enter the "www" when going to the install page, it sets the URL with the "www". Is it normal to default to installing without it? I guess that's just an aesthetic thing that the user can tweak, but I'm trying to prevent my clients from having to do tweaks unless necessary.