Add static link on custom content type

Issue Summary

Hi all,

I have a fairly simple use case but I couldn't find a way to implement it so far, so I hope someone will be able to help me on this.

Here's what I need:

I have a content type called opening (kind of job offer).
I want users to be able to apply to an opening by creating another content type called Application.
To do so, I would like to have a link field on my opening content type (Title would be 'Apply') that would point to node/add/application (static link, no need to modify it) and somehow the add application page would have its Opening entity reference field non-editable and prefilled with the Opening the user wanted to apply to.

So there are actually 2 questions here:
- How can I add a static url to a content type? (In this case the url would be node/add/application)
- How can I pass parameters to the add content page to prepopulate the entity reference field?

In another forum I've been suggested to look at webform module but to me this looks like something doable with links, am I wrong?

I hope this will make sense to some of you, any help would be greatly appreciated.

Thanks in advance for your help.

Simon