If you have to adjust your opening due to your opponent applying massive pressure, you shouldn't play all of that economy. Depending on how much pressure they are applying, you may only get away with the first round of economy before switching into defense, which is what I would probably do against the Rushmaster. You can play a second turn Barracks and a Brace Yourself turn 2, but that would work better if you opened with a card other than Meditation Amulet. I don't think it's that efficient to play Meditation Amulet turn 1 when you can deploy it out of your Battle Forge later if your opponent isn't rushing.
In general, if your opponent is applying a lot of pressure to you, you shouldn't keep playing economy. You may be able to get away with one more round of economy with the use of Brace Yourself and/or Block though. You don't really want to play most economy late in the game because it will be too late for it to benefit you that much. If your opponent plays zero economy, and you are generating a few extra mana/round and maybe an extra action/round, you will eventually overwhelm your opponent with superior resources if you manage to survive that long. This is particularly true against the Rushmaster because of her lack of long term threats. Just playing a few creatures should give you the long term advantage against the Rushmaster. You don't need all of that economy to win the long game in this case, and you have more important concerns than getting up your whole engine when your opponent plans to throw a boulder at your head every turn.