Is it a good idea to push a "lawn roller" over an area after having tilled it before planting gr seed?

Much depends on your soil type. Heavy clay soil must not be compacted. Light sandy soil can be levelled with boards as you suggest. But as in my answer to your other question, you would be better now to leave it over the winter, when it will have compacted by itself and will only need a light raking. October is really too late for successful lawn sowing - you can't depend on the weather not turning cold.