Is there any blame in delaying prayer beyond its time, or missing congregational prayer, due to waiting for urine to dry after urinating, and what about something coming out after ghusl?

There is no harm in placing a piece of cloth for protection from urine, then removing it and washing the urine spot after it ceases. Removing impurity takes precedence over attending congregational prayer, even if it leads to missing it, because avoiding impurity is a condition for the validity of prayer. It is not permissible to delay the prayer beyond its prescribed time due to an inability to remove impurity; rather, one must pray according to their condition, and the condition of avoiding impurities is waived due to inability.