Whois Record - Last updated - Why is this?

Normally it would be the registrant (the individual)
The billing address would be as you say the web design company that helped him/her register the domain.
It depends how the domain was setup originally. As an example I register on behalf of our clients the domain name, so in my case therefore, although the client is the registered owner, the domain renewals come through to me. I then let the client know that the domain is due for renewal, and if he or she does not renew it, I then either can lapse the domain, or in some cases, renew and use the domain for other purposes, perhaps advertising, or just keeping the domain name because I feel like it.

I'm not sure if this comment helps or not, but as I did say previously, also consider other possibilities on domain names. Not all may be lost, and although a domain name may be important, a better written and feature website will have the winning formula

Playdo wrote: In your experience as a company, you wouldn't set the domain up for auto-renew, you'd contact the client and then manually renew instead? Typically how long in advance would you contact them before the renewal date?

I would not typically set up the domain on auto-renew.
I would contact the client typically 30 days in advance, and expect payment before the renewal date of the domain. Depending on the client (do I know them, had good dealings with them, etc) would then make me decide do I renew it on my own initiative, and take a chance, or leave it to lapse. I guess therefore it might be a waiting game on your domain name. As I did say earlier, if you wanted to PM the web address (no I would not steal your idea), I'd be happy to give you a better informed answer via PM as well.

It would be imprudent of me to do anything like that, and believe it or not, I take client confidentiality very seriously. Have a good evening