Yes, Sitefinity has always been a pain at start up. But this can be said for ASP.NET web Form apps in general. The need to load everything on App Start. Coupled with this with the amount of dlls in the bin directory and the fact that they support multiple techs, for example, WCF, WebAPi, and Service Stack for Web Service calls which are all loaded as they are used in different parts of Sitefinity functions.
Though in your case things do sound even worse. (I'm about a minute which annoys me still)
I have no idea of your setup of course but life is better when the Database is local, or at least on a near by server. (Ie you are not developing locally and using a database up I the cloud in another continent.)
I had one person affected badly because of their Anti Virus. You can look to exclude your source folder from Anti Virus scans.
Use IIS or IIS Express to run the site.
There is also a good post on Google Groups, discussing this. That may help you.