This is a weekend so lets be a little patient here thanks.
1. Are there different themes available (both free and paid) for Photopost Classifieds? Is there a site where I can view sample themes?
Yes there are over 10 themes included with the product.
2. Is it possible to rewrite the URL of the Member Page to something more SEO friendly? For example, I noticed that the Member Page is something like http://www.classified-ads-site.com/member.php?uid=1234
... is it possible to rewrite the URL to become http://member-name.classified-ads-site.com
I'm a noob at this that's why I'm asking.
That would be something you would have to do and depends your mod rewrite urls and however you code up some modification. Our scripting performs and has the users you see. Our spider urls replace ?& and other characters with / which makes it easy for bots to crawl the urls.
3. Are the URLs of Photopost Classifieds SEO-friendly? Is there a plugin or hack that would rewrite URLs, if for example the advertised product is a brand-new iPhone under the Cellphones category can the URL be changed from say http://www.classified-ads-site.com/s...p?product=2877
read my post above for how we do spider urls.
4. Can users post tags accompanying their classified ad? And can this be programmed to be required to users as well?
sorry have no idea what you are asking here
5. Does Classifieds have a way for users to renew an expired ad? Say, an ad expired after 30 days, is there a simple button to click to renew the ad for another 30 days or does the user have to rewrite the ad again?
The user is emailed within 3 days of the ad expiring and in that email is a link to relist the ad as well as when viewing the ad there is a relist link.
6. Does the stand-alone version have a comment system where other users can post questions in one's classified ad post?
Yes there is a comment system included within the product.