Kavana in Kriyat Shema

will likely be the next in my series. This article in Machanayim by Prof. Yisrael Ta Shema is a good source for this - that while there is a general dispute whether mitzvot require intent, by Shema there is a separate issue, and definition, of Kavana to accept the yoke of God that is required. See Rashba, Rambam, and suppercommentaries there. I don't have the time to process all this right now, but it is something worth checking out.