Lowe's Business account, Personal guarantee, and LLC

I have a tendency to overthink things, so please bear with me. I hope I describe my thoughts clearly. As I continue my investment journey, I've thought about opening up a business account with Lowe's or Home Depot. I have an LLC, with an EIN number. When I look at the application, it asks for my SSN, and to sign a personal guarantee. The personal guarantee I don't have a problem with. My concern is giving my SSN. I'm re-building my and fiercely protective of inquiries and my score. Will they run an inquiry?

Second is my efforts to keep my personal finances and business expenses separate.  If I am using my personal financial standing and credit history to obtain credit for my business, could that be seen as co-mingling funds, and thus, put me at risk for "piercing the corporate veil"?

Any thoughts would be appreciated.