Trying to find the post ID of registration page

Hi there,

I'm trying to set up a workaround for the problem with Membership of people being able to sign up to the site without having to complete a subscription (in my case, there is very little content blocked, the client wants the functionality to allow people to pay to join their organisation online).
I've read some of your other articles on the issue, and in my case I'm using this approach:

1/ Upon login, determine if the site visitor has a subscription (I've got this sorted)

2/ if they haven't, immediately redirect them to the 'Join' (registration) page.

3/ hide any buttons that let them access any admin areas.

I've two questions:
1 - Any built in function for me to find the post ID of the registration page via Membership settings?
2 - Can you see any issues with the approach I'm using (I'm a bit of a php newbie).

Thanks for your help,