There is usually a host on duty in the back of the BConnected booth at Sam's LV. You can ask to speak to the host on duty and introduce yourself and ask what ever questions you have about what you might receive for your level of play. The advantage to going to the booth on a day/time you usually play, is that you will usually find a host that is on duty during the times you are there. For example, if you are a morning person, and you go to the both in the morning, that host will likely work early hours, vs randomly picking a host who you might find works days/hours that you are normally not there.
I personally don't see the list of advantages to be as great as stated above. For instance, if you are playing at a level where a host will host you, then you are already getting comp rooms for every night, and tournament invites. You pretty much confirm that in your question (you are getting rooms and comps already).
As far as the $1 for 4 hours. That is a general guideline that I don't see applying these days. It all comes down to your theoretical loss. You can play a machine that has a higher theoretical loss, and put in much less coin in, yet get the same offers/comps as someone playing much more at a full pay VP machine with a low theoretical loss. There are MANY variables, not just $1 for 4 hours.
As far as playing at mutiple Boyd locations... don't play more than one location on the same day, because each of the locations will count that as a day of play. You are always better off playing in one place over two in a day. If you want to play at another Boyd place, consider playing there on a day you aren't staying at Sam's.
Since you are not new to Sam's LV, I see your out of state play as having no impact on your comps in LV, with the exception of your card level (Emerald, etc). A host is not going to comp you a meal in Billy Bob's based on your out of state play when you already have play history at Sam's LV.