We do not offer Home Equity Lines so I can't speak to that, but based on your description I'd say:
1) you may access a credit report for a business reason and you likely have authorization in your files to this based on the existing relationship.You have a legitimate need.604(a)(3)(F)(ii)
2) as you noted, they didn't apply and further, you took no adverse action, you just didn't offer them new terms.
3) I'd question more whether the intended purpose here is a pre-screening effect and what implications could be caused by that.
Opinions stated are not necessarily that of my employer.