It is pointless speculating about some hypothetical Aramaic original because we do not have access to such a text. The first Aramaic text of the Gospels came at least 50 to 100 years after the existence of the Greek text.
So, all we have is the Greek text so i will confine my comments to that text and the use "[The] Son of Man".
1. Inarticular Υἱὸς ἀνθρώπου
This phrase, without the article occurs only four times in the NT, namely John 5:27, Heb 2:6, Rev 1:13, 14:14. The equivalent phrase in the Hebrew in Ps 8:4 (quoted by Heb 2:6) is also inarticular. Both Rev 1:13 and 14:14 allude to Dan 7:13 which also lacks the article. In all these cases, they refer directly to Messiah, Jesus Christ.
2. Articular ὁ Υἱὸς τοῦ ἀνθρώπου [Literally, The Son of the Man]
This phrase with the articles occurs 82 times in the NT, eg, Matt 8:20, 9:6, 10:23, 11:19, 12:8, 32, 40, ... John 13:31, Acts 7:56, etc. Again, these all refer directly to Jesus Christ.
The phrase "son of man" occurs many times in the OT, mainly in the book of Ezekiel, viz, Eze 11:15, 20:3, 21:19, 24:25, 28:2, 33:2, 12, 36:1, 37:19, 38:2, 39:17, 43:7, 44:5, etc. All of these refer directly to the prophet Ezekiel taking direct instructions from God. They lack the article.
From this survey, the NT usage of the title "Son of Man" whether articular or not, we may infer the following:
- "Son of man" refers exclusively to Jesus Christ, in the NT
- This title of Jesus emphasizes His humanity which the NT is at pains to stress, see, Phil 2:5-8, Heb 4:15, 1 John 4:2, 2 John 7,
- This is confirmed by the fact that Jesus died, Matt 27:50, Mark 15:37, 44, Luke 23:46, John 19:30, 33, 34, 35, Luke 24:46, 1 Cor 15:3, 4, Acts 10:40, 13:30, etc.
- The use of articular and inarticular forms of the title, "Son of Man" appear indistinguishable in their use in the NT - both refer to Jesus with equal distinction.
Now to Mark 2:1-10. The story hinges on the fact that the listening Jewish leaders were aghast at Jesus forgiving sins (V6, 7) - because only God can forgive sins.
Now, it is true that the NT teaches us to be forgiving and to "forgive one another" (Eph 4:32, Col 3:13); however, the only sin that a person can forgive is the sin or offense committed by someone against that person. Humans cannot forgive sins generally. This was the subtle point picked up by the Jews - Christ forgave sins that had not been committed against Him.
For this they accused Jesus of blasphemy; but such a charge is only valid IF Jesus is not God which the NT goes to some lengths to establish, Matt 1:23, John 1:18, John 5:17, 18, 23, 20:28, Phil 2:5, 6, 1 Tim 3:16, Titus 2:13, Heb 1:8, 2 Peter 1:1, etc.
That is, during Jesus' incarnation, He put many of His divine prerogatives aside (Phil 2:5-8), but, according to Mark 2:10 (and Matt 9:6), the forgiveness of sins was NOT one of these - Jesus retained to privilege of forgiving any and all sin while on earth.