I assume you meant to say the /wp-admin BulletProof Mode is not activated correct? Is this a single site or a WP Network installation? Did you use the AutoMagic buttons to create your master .htaccess files? BPS should work the same in a typical shared hosting environment as it would in a vps environment. Dedicated hosting could have some conflicts, but no one has every reported back to me that they have had any issues with dedicated hosting and BPS. Also when it comes to htaccess files in general it should not really matter what type of hosting you have as long as the directives in your .htaccess file are correct.
Not being able to view a post is most likely either going to be because you do not have a custom permalink structure or a valid custom permalink structure. This could also be caused by not having the correct RewriteBase and RewriteRule in your root .htaccess file. And it could also be caused from the wp-admin .htaccess file not being seen or not being activated. If this is a single site then recreate your master .htaccess files again using the AutoMagic buttons. Then go the BPS File Editor and make sure that the correct RewriteBase and RewriteRule are being seen by BPS. BPS gets that info from your WP General Settings information. If there is a mistake in those settings then BPS cannot automatically fix that mistake. Check your custom permalink structure to make sure it is valid. Then Activate BulletProof Mode for your Root folder and Activate BulletProof Mode for your wp-admin folder. Thanks.