Re: One Page Checkout: Personal Information
 

That is how X-Cart OPC works (terrible UX) -- but...
That is NOT how Checkout_One works.
That's why I do not use X-Cart OPC checkout and instead use CheckoutOne

Re: One Page Checkout: Personal Information
 

For guest customers we have disabled all Personal Fields except Company Name. If they register then we allow (but not require) the following personal fields: First Name, Last Name, Company, URL.

The personal name fields are helpful because some of our customers use their boss's card to make corporate purchases. So it's good to know the actual person's name that is making the purchase in case we need to call them.

Given our setup, it looks like you can disable all the personal fields without any issues. Just try it and test to see if it solves your issue.