I'll start with your initial problem from this post
Let's call the sound shifting code the 'ShifterPatch' 
In the first image, you had not installed the ShifterPatch, ToBEx was installed with Existance Sounds Fix = 1 and -TEST01.CRE has the "Have a look..." strref (#38783) at EXISTANCE2.
Assuming that the CRE in question comes from vanilla BG2-ToB or from some mod made for BG2-ToB, -TEST01.CRE was made with the intention of #38783 being fired when the BG2 engine runs the 'fidget loop' as A64 calls it. During the fidget loop, the engine picks one of an array of 5 sounds and plays it as an ambient.
The array of 5 sounds is starts at the sound at offset 0x1b8 of a CRE. These are:
0x1b8 PICKED_POCKET
0x1bc EXISTANCE1
0x1c0 EXISTANCE2
0x1c4 EXISTANCE3
0x1c8 EXISTANCE4
ToBEx corrects that fidget loop function to pick the array of sounds from offset 0x1bc of a CRE. Causing the new array to be:
0x1bc EXISTANCE1
0x1c0 EXISTANCE2
0x1c4 EXISTANCE3
0x1c8 EXISTANCE4
0x1cc EXISTANCE5 (was unused in vanilla BG2-ToB - like the ToBEx docs say)
In light of the above change, what you notice is right - PICKED_POCKET sounds should be moved to EXISTANCE1. But the same shifting should be applied to EXISTANCE1-4 irrespective of whether PICKED_POCKET is set or not.
Please note that the pre-ToBEx position of EXISTANCE2 in the fidget loop array is 3rd - post-ToBEx, the 3rd position is EXISTANCE3 - which is where -TEST01.CRE's #38783 was shifted to by the ShifterPatch. So I fail to see why -TEST01.CRE should have been skipped by the ShifterPatch is what I'm getting at 
Re: Script Commands
When I posted that I was thinking about SetPlayerSound() but I just did a grep and they are mostly used by NPCs to set their BIOGRAPHY string (which is also coincidentally EXISTANCE5 before ToBEx happened
)
On the topic of VerbalConstant() I see lots of mods do use it but none of them use the EXISTANCE sounds (or PICKED_POCKET for that matter
)
Re: Overwriting EXISTANCE5
I imagined a case where NPCs who were kicked out and waiting at a hub location were all screaming like "OOooh I picked a pocket", "Picking their pockets" and other variants of PICKED_POCKET but we'll see if and when that happens (would actually love to see it happen
)
K4thos' filter does a pretty wonderful job anyway so yeah I'll remove the EXISTANCE5 check 