Yes I have read this before, its well known. This does not apply to Jeremy's situation at all. There is no rope at all, Just a spiders web of lies. That is why you never bothered to post "the massive list" because its too embarrassing and you know it wont stand up to scrutiny. 
There's a huge list why Jeremy is guilty. He was frustrated with a life where the standard of living he required was always out of reach, where he was expected to graft on the Farm when as he perceived it Sheila was living it up in Moreshead Mansions with nothing to do all day save lie in bed. He caught wind of the seriousness of her illness probably from Barbara Wilson, who may have told him his sister's thoughts that "
all people are bad and should be killed." Rather than expressing sympathy as most family members would have done he conceived a plan, dictated at various stages those preceding six months to Julie.
In a sense we know the outline of that plan, which according to Jeremy post-event was the "perfect crime". This tells us that things did run smoothly, the first time he was truly in control after an early years experiencing nothing but alienation on the Farm, eight years at Gresham's as an automaton, further ordering around at Sloppy Joe's and Little Chef, the foreign trips where his parents ultimately controlled the purse strings and back to farming, to which he was tied by the terms of his father's will until he died.
It's important to understand that he had followed orders all his life and was never in a position to give them. It's why I exonerate Julie to some extent because taking orders was anathema and he vowed things would be different with his parents out of the way. Sheila would be set up as patsy, but she and the twins were a mere appendage: the main goal was the liquidation of his parents as retribution for the way he perceived he had been treated all those years: abandoned at birth, neglected at home due to June's illness and her inability to empathize, packed off to Gresham's for eight years, where every school holiday the estrangement became ever more severe, until finally he admitted to Julie
"they have forfeited the right to live the way they have treated me."
As his confabulation became ever more vehement and Sheila's illness became all the more severe his resolution became stronger, strangling rats with his bare hands as the family folie a trois spread, the murder plans now seemingly a part of his daily routine as he sat inside the cannabis haze of the tractor and pondered his future. With the lightning strike on the Farm and Nevill's non-functioning mobile telephone coinciding with Sheila's visit it really was "
now or never" as he told Julie, the chemical excitants exercising far more wayward control of his brain than his parents ever did in life.
And there we have it. No telephone call from Nevill because Jeremy was the ineffectual nonentity who went through the motions, who wouldn't use the crop sprayer, who wouldn't wear a shirt and tie at his father's request and who was only in the rank he occupied due to an accident of birth. Nevill couldn't conceal his disappointment at how his son had turned out and Jeremy felt it, though by now the time for self-recrimination had long since passed. No use of a gun by his gullible schizophrenic sister, a recovering anorexic suffering from Tardive Dyskinesia, whose coordination issues precluded her from driving, from pouring a drink without using two hands to steady the glass and who was thoroughly dependent on her rich parents the same way Jeremy was, though a gulf in colloquy existed between the two. It's why Jeremy can't bear the sight or sound of religion as he looks back in retrospect at the perceived damage it inflicted on mother and sister, why there is no sentiment of Christian repentance and why he hangs onto some feeling of superiority as in his own mind he emerged unscathed from that folie a trois and reverts to obeying orders from his prison cell where a sense of normalcy once again pervades.