The removal of pews from Roman-rite churches would require the education of the faithful on what to do during the liturgy - ideally it would probably be concurrent with other changes in the liturgy, though I suppose the typical English OF liturgy could be implement this change - would standing enable people to realize how inadequate contemporary American liturgical music is? Or would we see more ridiculousness - clapping, stomping, swaying, and such?
Having attended the Anglican use liturgy at Our Lady of Atonement (which has incorpoated some "Eastern" elements into the texts?), it might be the case that the laity could adapt to a more "traditional" way of worship more easily, once the pews were removed. Which reminds me - isn't kneeling a rather traditional posture in the Roman rite? Would the laity be able to do so for along period of time without some sort of kneeler? Kneelers are conveniently built into the back of pews - without pews, would churches be willing to purchase prie-dieus? I personally do not like the use of carpeting inside churches - without pews and carpets, would the use of prayer rugs become acceptable? Or prayer knee pads? There is kneeling in the Byzantine rite, but it seems to be for shorter periods of time than in the Roman rite. There has been a movement by some Roman-rite liturgists and bishops to replace kneeling in the liturgy (particularly during the Eucharistic Prayer) with standing, though this has been resisted by those who are more "conservative" or "traditional" (and this preference is still protected by instructions from Rome). Standing by itself seems to be an insufficient acknowledgement of what takes place during the Eucharistic Prayer - and yet I've never heard anyone say that the faithful should bow or do any other external action - this may be done by some, out of some sort of instinctive awareness that they should do something more, or as an adapting of the observances they practice while kneeling, or because they are somewhat familiar with Eastern customs.