You have to be a Legacy CC member to even have an option to buy lower bowl seats. If his date is 7/18 that means he is probably a Bronze CC member so lower bowl won't be an option at all.

As for priority for future years, they only look at the number of years you bought tickets - not the number of tickets bought. Priority is treated the same whether you get 2 seats or 4 seats.

You can often times get lower seats for a lower cost w/ bleachers compared to the upper chair seats, so if you don't care about having a chair then it could be a great option.