We have a current eCommerce Site that runs on ASP.NET and we hired a consultant to develop an new site bases on SOA. The new site architecture is as follows

1. Web Application : Single Page Web Application (built on javascript/jquery templates - do not use any MVVM frameworks) that uses some javascript thrown all over the place.
2. Service Layer : Very very light Service Layer that does not do anything other than calling a single stored procedure and pass in the entire http request.
3. Database : The entire site content is in the database. The database does the heavy lifting of parsing the request and based on the HTTP method and some input parameter calls the appropriate Store Procedures or views and renders the result in JSON/XML.

We have been told by them that this is built on latest and greatest technologies. I have a lot of concerns and of them given are the few

1. Load on the Database
2. SEO concerns for single page application as this is a public facing website
3. Scalablity?
4. Is this SOA?
5. Cross Browser compatability (Site does not work in < IE9)
6. Realistic implementaion of Single page application

I know something is not right but I just need to validate my concerns here. Please help me.