Hi @anon37242974, welcome to the Asana Community Forum!
As it stands, it’s currently not possible to customize the forms URL. As a workaround, you can try YOURLS (https://yourls.org/ ) to make the URLs shorter and customize them.
In regards to your second question, it’s currently not possible to manage forms permissions, I suggest you to add your vote here: [Forms] Ability to manage Forms permissions
We have launched some updates recently for Forms, you can have a look at all new updates here: Forms are now even more powerful and customisable!
I hope this helps!