I think that you should have major problems with how you are interpreting those verses as speaking against obeying what God has commanded, but even if your interpretation were correct, then according to God's word in Deuteronomy 13:1-5, you should consider the author of Hebrews to be a false prophet who was not speaking for God, so we should still obey what God has commanded regardless of whether or not your interpretation of those verses is correct. The bottom line is that we must obey God rather than man, so if it comes down to a choice between obeying the book of Hebrews or obeying what God has commanded, then we should obey what God has commanded.
are all in perfect harmony with each other. Should a schism exist, then none of its books, not just Hebrews, can be trusted as the supreme and sole spiritual authority, and all of the spiritual truth conveyed must then be discarded - it is an all or nothing proposition.
Do you realize the Bible was written by God from beginning to end, to be solely about Christ - that He was the reason for it all:
[Psa 40:6-8 KJV]
6 Sacrifice and offering thou didst not desire; mine ears hast thou opened: burnt offering and sin offering hast thou not required.
7 Then said I, Lo, I come: in the volume of the book [it is] written of me,
8 I delight to do thy will, O my God: yea, thy law [is] within my heart.
[2Ti 3:16-17 KJV]
16 All scripture [is] given by inspiration of God, and [is] profitable for doctrine, for reproof, for correction, for instruction in righteousness: 17 That the man of God may be perfect, throughly furnished unto all good works.
[2Pe 3:15-16 KJV]
15 And account [that] the longsuffering of our Lord [is] salvation; even as our beloved brother Paul also according to the wisdom given unto him hath written unto you;
16 As also in all [his] epistles, speaking in them of these things; in which are some things hard to be understood, which they that are unlearned and unstable wrest, as [they do] also the other scriptures, unto their own destruction.