In regards to the advantage. The advantage should be seeding...even though Houston is just a team...they have our number...the find ways to beat us. There is also supposed to be an inherent advantage in hosting the second game and knowing what you need to do for the home game...and in the case of OT or PKs having that play out in your house instead of theirs.
One change I think would be worth considering (they do this is Mexico) is that in the case of a tie in aggregate instead of doing OT and PKs the higher seed wins the series. Not sure I am in favor of it but its compelling.