For the second sentence, "せめて" might be better in my opinion.

"at least" = "少なくとも"(sukunakutomo) or "最低でも"(saitei demo) these 2 phrases are same. - I exercise at least 3 times a week. 一週間に最低でも３回はエクササイズします。 - Come on.. at least let me have 1 beer. おいおい・・・少なくともビール一杯は飲ませろよ。 - We've got at least 2 more hours of work to do. 私達は、少なくとも もう2時間やるべき仕事がある

以上（いじょう） might be another word you'd like to use