Some people have to ask difficult questions LOL
The templatecodes system (templates and modules) is special in regard to
SEO. It is one of the great benefits of using it.
It has been designed so certain urls are 'nofollow' like userjoin, login, contact , etc. You should also put these urls into a robots.txt file so they are 'nofollow' as well to be certain. We don't distribute a robots.txt file because to be frank, people should be doing their own. They may have a whole range of pages they do not want to have indexed for whatever reason. Why have a search engine dilute what it thinks about your overall site as several other hundred people have the same pages - userjoin, contact, etc. They hardly contain useful information from a search engines perspective. These pages are worthless in
SEO terms and will probably be seen as duplicate content too (possible penalty - nobody is ever sure or knows).
Now the viewlistings and categories are a different matter.
You can remove the nofollow from the plugins and template files in the templatezones module (that is where they are set) but there is a good reason for it being like that.
SEO was my subject and one of the things about the templatecodes system is it guides a search engine to go through the whole structure of your site in an ordered nanner. The way "I" prefer it to do it having had some success in this area. Otherwise a search engine comes to your site and it runs off immediately to some obscure advert after reading a few lines of code. Is that what you want to say is important about your site - probably not. What the underlying structure of our templates does is take a search engine through pages of general importance (like a hierarchy), going to lower priority pages at each pass. For example, in principle it will go to browse page before an individual category or individual advert. It will find those after when it has got the browse page, category pages, etc. What search engines rarely do is index every page on your site in one go and put them in their results - it builds up over time; so make it easy for them to determine the most important pages in your site.
What the tc_sitemap module does for them is provide an overall map of the current site and importantly, when updates to urls were last made. This last point is important because it tells search engines not to crawl a url when it already knows the content. It saves a job and you probably win a few brownie points. It is only interested in new content at the end of the day. Things that have changed or new urls which are created. It knows the extent of the site too having a complete map of it. You can also put guidance into the xml generated sitemap about what urls you think it should prioritise.
What used to be done with the templatecodes system in addition (no longer) is to attach proper title tags to all internal links. The reason why this is not done since the original Nustyle template is that nearly every file in the defalut template would need to be touched and this just makes upgrade and support impractical. However, those that want to
SEO their site should think about doing this.
I cannot over emphasize what
SEO is really about though - its 50% about CONTENT, 40% what others (which others too) think of it and 10% internal structure - see the sticky.