1. Meta titles for ALL pages is generally a bad idea for SEO. They are hardly helpful anymore in general, but if you set them as same for all pages they make no difference at all for your SEO effort. It's important to set different descriptions and keywords for different subsets.

2. We don't rush into a GOogle Sitemap generation mostly because of configurable nature of UNA. You can change the structure significantly so that creating a sitemap for all situations is a going to make a complex module. 

The good news is that we already see that Google is picking up UNA site URL patterns very well. It can tell that Discussions is like forum and presents them so. It recognizes Posts as blogs and generally craws the site fully.