A couple of suggestions:
(1) If there is slow play, etc. you should not have to deal with it. You should tell the "Ranger" or "Ambassador" as that is what they are there for.
(2) Regading walking. We use to always tell the players that is it up to them to keep up with the group in front of you as opposed to staying ahead of the group behind you.
No one should be concerned about walking since as long as they follow rule
(2) above they are doing the right thing.
