Pesi said
The Forum link on the menu does not show up unless a viewer is logged in as a WP user (?)

That really depends on how your WordPress theme and menuing sustem is set up. It seems odd to have it set up that way and opresumably somewhere in your WP theme setup you can change that. It is NOT a Simple:Press issue as Simple:Press has nothign to do with menus,

How can an unregistered non-member view the site and then choose to go to the forum link to register?

The registration link on the forum is only there to help users who may not want to see it somewhere else - like in a sidebar for example. Users do NOT register on the forum. Registration - like login - is to your website

Also after registering, the viewer is taken to the WP dashboard and there is no clear way for them to change their password and be taken to the forum or the website itself.

But this is exactly how WordPress works. There are some options in the forum toolbox to help you change this and I would suggest you look through them. Biut if you want more control over the process then again - this is nothing to do with Simple:Press - this is down to WordPress your Wp theme and any plugins you have active. Grab a plugin like 'Theme My Login' (for example) and build the website the way you want it,.

Again, even if they go to the website (by clicking on the Visit Site link, they are taken to a screen which shows only the forum stuff - and only by scrolling down a lot, does the website with the forum page embedded, come into view.

This too will be an issue with your WP theme behaving badly and probably doing something non-standard. There are some display options on the wp integration admin panels that may help correct this but you would need to try them. These things are virtually always fixable.