Why are you interpreting "should" as "shall"? I interpret the word "should" as indicating an option, not as indicating a requirement.
And how do you construe To prove [Tyranny over these States], let Facts be submitted to a candid world. D of I.
Again, this statement does not assert a requirement that facts must be submitted before independence is valid. The argument of the natural law philosophers of that era were that Men had a right to self governance, and they did not need a King to rule them. They could rule themselves.
For some reason, you are offering the argument that the US would not have had a right to independence if the King hadn't abused them. You are arguing that had the King been kind and benevolent, we would have no right to leave his authority.
The natural law right asserted by the Declaration is that men have a right to rule themselves, and do not have to obey a King, no matter how he treats them.
Read Samuel Rutherford's (Cited in the debates on the Constitution) "Lex Rex."
So you're cherry-picking natural law right asserted by the Declaration which is why you don't like and apparently want to avoid the part of the D of I that says
- Prudence, indeed, will dictate that Governments long established should not be changed for light and transient causesor
- To prove [Tyranny over these States], let Facts be submitted to a candid world.
Indeed, the historical fact is that our Founders did not, at first, want independence.
What they wanted, instead, were their rights as Englishmen to representation in Parliament.
That's what "no taxation without representation" was all about.
And there was at the time serious consideration in England for admitting Americans to Parliament, proposals eventually rejected.
Still Americans did not immediately run off & demand independence.
Instead Benjamin Franklin continued to work in London for better terms and relations with the Brits.
Only in 1776, after the King effectively declared war on Americans, ending any possible peaceful negotiations, did Franklin finally return to Philadelphia to help author the Declaration of Independence.
So, in 1776 there was no "secession at pleasure", but rather independence dictated by absolute necessity from abuses, usurpations and despotism over Americans of our Founders' generation.