Stop in for a cup of coffee

As soon as Dave builds that, he'll have a couple of friends over and the tables won't fit or you need to constantly navigate between the grill and the table to get out into the garden.

Double it.
Depends on the yard size. A good argument for not building big -they do take a bit of maintenance to keep it nice. Could use Trex or other fake wood composite, but I am not a fan of those. Mine is pressure treated and needs to be sanded and refinished every few years. Mine is due for that (along with needing several boards replaced).