As per & as pertains

Is this correct? How would you use 'as pertains to' and 'as per'?
1 Would you please read the following sentence from a military letter to a state senator and correct it as pertains to using the word remain or remains?

2 I read the above thread but how would you say the below sentence as pertains to the above page about X?

Is as per used this way? What do you think about the grammar in the last sentence ?
3 As per hotel policy, kids more than 12 years old are not allowed sleep in a room with already 2 people as all room accommodate 2. The only exception is/being for kids under 12 who can sleep in little pull away beds.

Thanks