I think the following should help answer some of your questions:
Price Appreciation
vBNT burning creates a deficit of vBNT, relative to all active BNT stakes. Since vBNT can be obtained from creating a new BNT stake, the only feasible avenue to retrieve older BNT deposits (which have appreciated in value), is to buy and stake more BNT. This creates a new type of economic demand for BNT, that should serve to drive its price up over time.
The market efficiency associated with vBNT swaps supports new and creative financial strategies. The availability of these options to participants on our platform, and their absence on rival exchanges also bolsters organic interest in Bancor, and increases the fundamental value proposition of owning BNT.
The most important function of the Bancor Vortex is to create a magnetic attraction between market BNT and the protocol. To investors, the consistent rise in TVL is of special interest, as this metric is a primary indicator for BNT price speculation. Faster, and more sustainable protocol growth inspires market confidence, and therefore improved price evaluation by spectators.
But I recommend reading BIP9: Proposing the Bancor Vortex in full to get an understanding.
Generally, when an asset is scarce in a pool then its value goes up and the opposite happens in the other direction. $vBNT has large liquidity in Uni v3 at the moment so anyone can arb the pool by adding vBNT removing BNT and selling BNT to bring it to equilibrium with the price of BNT every where else.
It is also good to note that vBNT burning does let us lock BNT tokens at cheap rates as folks that leverage help push the vbnt-bnt rate lower. This is beneficial since we do get more bang for our buck essentially and overtime I think does have an impact.
I went ahead and added for/against clauses to your proposal so that Bancor DAO participants know what each option will do.