Upgraded!, you are interpreting the rules correctly. Ticketing deadline means that a passenger has however many days to pay for the ticket and for the agent to issue the ticket.
Many people do place reservations on hold for a few days or for a week. There are fully flexible fares that do not have advance ticketing requirements at all and people pay for them and have the ticket processed a day or a few hours before the flight.
It is not possible to do it online though. Another thing to bear in mind that airlines may (and do) issue a new ticketing deadline prompting the agent to issue a ticket sooner (if the flight is filling up quickly, for example). With AA these deadlines usually correspond to the maximum term allowed by the fare rules. BA also always issues the longest possible deadline. For mixed itineraries each airline in the reservation may set its own deadline irrespective of the rules - for example, BA WTP fares book into 'H' or 'B' on AA domestic flights, but AA has no way of knowing that most BA's WTP fares allow up to a week to pay for the ticket and will issue its own deadline that must be honoured or it will cancel its segments. The work around is to book under a BA codeshare flight number but not all flights can be booked as codeshare.