If you noticed I said there are obvious additions and interpolations through copying, translation and revision (just as in the "canonical" new testament).
Many old texts were revised to fit the current (at the time current I mean) position of the Church.
My opinion of the Didache is that is was origionally Aramaic (of which fragments have been found) or possibly even Hebrew and was a well-known church manual (seeings that fragments containing its words are found in Coptic, and even Arabic) which was edited in its translation to Greek.
"1:1 There are two ways, one of life and one of death, and there is a great difference between the two ways."
The analogy of "the two ways" reflects the Jewish tradition.
1:2 The way of life is this.
1:3 First of all, Love God who made you;
1:4 Secondly, Love your neighbor as you love yourself.
1:6 Now of these words the doctrine is this.
1:7 Bless those who curse you, pray for your enemies, and fast for those who persecute you;
1:8 For what thanks do you deserve, if you love them that love you? Do not even the Gentiles do the same? But do love those who hate you, and you will not have an enemy.
8:1 And let not your fastings be with the hypocrites, for they fast on the second and the fifth day of the week;
8:2 But do you keep your fast on the fourth and on the
preparation day.
This passage makes mention of the Preparation day before the Sabbath, which means the person who wrote this part most certainly did not keep Sunday or "The Lord's Day"
8:11 Pray this three times in the day. (In refererbce to the Lord's Prayer)
This another Hebraic practice (see Psalms 55:17 and Daniel 6:10.)
13:1 But every true prophet desiring to settle among you is worthy of his food.
13:2 In like manner a true teacher is also worthy, like the workman, of his food.
13:3 Every first-fruit then of the produce of the wine-vat and of the threshing-floor, of your oxen and of your sheep, you shall take and give as the first-fruit to the prophets;
13:4 For they are your chief-priests.
Yet another Hebraic practice, the first-fruits offering to the Priesthood.
Now I can see no fault with this passage, and the majority of the text. But, as you pointed out the false ideas of "the Lord's Day" (which the same term in found in Revelation) and the Eucharist, a few other passages bother me as well. Such as the baptismal passages and these:
4:1 My child, you shall remember night and day him that speaks the word of God to you, and your shall honor him as you do the Lord;
4:15 But you, servants, shall be subject unto your masters, as to a type of God, in
and fear.
I except only the Tanakh as inerrant scripture, though I can see inspiration in many New Testament books and some outside of them.
The canon of the New Testament was established hundreds of years after Christianity had been ethnically cleansed of Judaism, after Constantine remolded the religion as a method of control.