Since you did not specify as to which poker format you were referring to [Online or Live] I will take it that you are referring to online tournaments.
1] Actually having a player sitting out is a bonus for the table because any active player at the table has the opportunity to take the players ante’s and blinds.
2] not quite sure what you mean on “should there be a time for a player to act before their position in the tournament is expired” there are time outs that everyone has to act on before their
hands are dead, but if you are referring to having the player kicked out of the tournament if they are not active, then [
ABSOLUTELY NOT], it is the same thing as if you purchased some tickets to see a concert or movie, should the administration of these events take away your seats because you did not arrive on time or were extremely late to the events .............. [
ABSOLUTELY NOT] ...........