1) Ch. 1, v. 3: "Lirtzono lifnei Hashem" With his willingness in front of Hashem The previous words "yakriv oso" seem to be contra-indicative, that he MUST bring the sacrifice.
2) Ch. 1, v. 9: "V'kirbo uchro'ov yirchatz" And its innards and its legs you shall wash We do not find this command by chatos, oshom, or shlomim. Why?
3) Ch. 1, v. 14: "V'im min ho'ofe oloh korbono laShem" And if an avian offering is his oloh to Hashem "LaShem" is mentioned here and not by the bovine or sheep offerings. Why?
4) Ch. 4, v. 27: "V'im nefesh achas techeto" And if a single soul will sin What it the intention of "achas?" The verse seems to be fine without this word.
5) Ch. 5, v. 15: "Ayil" A ram Rashi says that a ram is in its second year. Why does Rashi wait until here to give us this information? We find "ayil" earlier, for example at the end of parshas "ho'akeidoh."