In the league I'm in, we have a huge sub list, and there are teams that use it all season long. However, we have to have 3 regulars on each team every week for the individual and team wins to count.
As for pre/post-bowl, we allow it but it is up to the team captains to give advanced notice. No notice, no pre/post bowling. That happened in November where the team I'm on ended up bowling unopposed because the other team of 5 never gave any notice. Usually, it's not a problem since the teams know they have to field at least 3 regulars and can go through the sub list.