Once or twice a week? How about 'not ever'?

If the section started to get flooded with numerous FS post, it's possible that someone could get moved back a page or two where nobody will look. I think once a week is a reasonable compromise.

I think the seller can edit it out of the listing.

True, but it should be pointed out in the opening "sticky"

If someone wants more info, they should contact the seller via e-mail

I think things like specific model, year, condition, etc... are things that should be in the initial post. If they aren't, then I think it's reasonable enough for someone who might be interested to ask about these things in the post.

If someone thinks they've been jerked around, that can get into some messy areas in terms of the site's rules about bad-mouthing other members.

This is true. This is something that should be stated in the "sticky."

You're probably right.

Of course I am..... :D j/k ;)

Thanks for the offer.

No problem.