ballukku - (an aromatic substance of vegetal origin; the tree which produces this substance), perhaps styrax (CAD B 64, AHw. 100)

It is conceivable that Akk. ballukku and Sum. (šem)bulug were borrowed independently from a third language.

balsû - (a mark on the liver) (CAD B 65, AHw. 816)

Or palsû.
Probably of Sumerian origin (perhaps a “learned” loanword), but the etymon is obscure.

baltām(mu) - balsam (SAD I)

A WS lexeme with the lateral sibilant *ŝ, appropriately rendered with the combination -lt- in the cuneiform (Jursa 2009, 156f., Kogan 2011, 78). Cf. Pho. bšm “perfume, spices” (DNWSI 203), Hbr. bōŝäm, *bäŝäm, *bāŝām “balsam tree, balsam oil” (HALOT 163), etc.

baltu - (a plant) (CAD B 65, AHw. 100)

The original form is baštu rather than baltu (George 2016, 113f.). No etymology can be suggested.

balu - without, without the consent of, apart from, in the absence of (CAD B 70, AHw. 100)

See related forms with the suffixed -t: OA, NA balāt 'apart from' (CAD B 45, AHw. 101), OA, NA balāt 'apart from' (CAD B 45, AHw. 101), MA balut 'without' (CAD B 76, AHw. 101).

bālu - “nothingness” (designation of the planet Mars) (CAD B 74)

Or. ballu.
No definitive etymology can be suggested. In Oelsner 2005–2006:121 and Horowitz 2014:234, fn. 1584 it is proposed to derive bālu from baˀālu 'to be large'. This interpretation, although semantically plausible, is hampered by the absence of the “strong aleph” in bālu (one would expect *baˀlu).

balû - to become extinguished, to come to an end (CAD B 72, AHw. 121)

Var. belû. Derived words: belû 'extinguished' (CAD B 94, AHw. 121).

bamātu - open country, plain (CAD B 76, AHw. 101)

The only transparent cognate is Hbr. bāmā “open (hilly) country, hill, highland”.

bamtu - chest (CAD B 78, AHw. 101)

Clear-cut cognates with anatomic meaning are found in Ugr. bmt “back, rump, loin” and Hbr. *bōmät “back” (HALOT 136).

bamtu - half, half shares (CAD B 77, AHw. 101)

Var. bantu, pandu.
Cf. bamāniš 'in halves' (CAD B 76, AHw. 101).
No definitive etymology can be suggested as no clear Semitic cognates with comparable meanings have been detected.