Do Match Play scores affect my Average Score or Tier ranking?
Yes, Match Play games do affect your score average and your tier ranking. If you play a match play game against a player of higher tier and win the match your score average will be affected which could affect your tier ranking.
pdb1:it help your average more to compete and win against a higher tier and or hurt your average to play against a lower tier?
You benefit from beating a higher tier.
You dont lose any from losing to a lower tier
Match play is described in detail here:
Scroll down to the section on match play points; your answer is in there.