I'll try to answer some/all of that
Re Levy - He did a lot for the club, a lot that will keep paying off decades into the future. His football failures are vastly overstated, the club went from a previous decade+ of only finishing in top 6 once and not playing in Europe for over 20 years to finishing in top 6 with 3 exceptions in 17+ years, two trophies (not good enough) and the club's best run of places in the top flight in it's history (not PL history, total). And all of his failures have to be caveated with competing against the cheating of Chelsea/City and Saudi Sportswashing Machine, London fudging with us over Stadium planning/approval for a decade, Covid just when Stadium came online, and the true owners who would not invest into club. He also had some tie in (even if just a lifetime/25 years of personal investment to club)
I think what most people want is leadership (good or bad), and Levy was that, and we all know Frank would have been gone long before the club got to a risk position, and even it would have been panic buys in January, we would have bought (he wouldn't risk club status). Viani/Lange are not leaders, they may be competent in -1/-2 roles but they have shown not to be leaders.
Levy to me will become like the Ange conversation, you have to separate the "was it smart/right to move them on" from "we replaced them with brick"
Commercial success is critical, I know it winds fans up, but it's the reason Leicester won the PL and FA Cup and are two tiers down now, is because they didn't raise their commercials to match their success. Levy deeply understood this, when you look at the PL revenues, there is a massive gap between the top 6 and the other 14, so even when Spurs, United, Chelsea drop out of top 6, it really doesn't change anything because the 7th best side with earn 200-300M less per season, over 5 or 10 years that is an insurmountable advantage. No amount of smart club running will overcome that, Brighton, Bournemouth, Bretford will never replace the top 6 clubs and probably all will drop out of the PL in the next decade.
Now to pieces I 100% agree with, consistent football philosophy, the swings have hurt us with a squad built for multiple managers, it also dilutes our brand having Conte/Jose/Frank type managers, more than most we have had a claim to at least trying to play entertaining football. That said as fans, we would have to accept that a club that runs that way will not hire big name managers (unless you get very lucky and find one that somehow plays your style), Spurs may have to be content with more "aligned to attacking/possession" than say a scenario where club dictates style/formation/players and managers align (and I'm not sure any elite club does that anyway)
Re sale of club, I don't think it happens, and the chances of it happening with a good outcome is pretty low
- The last two big owners in PL are Saudi Sportswashing Machine and Chelsea, Chelsea is an utter clusterfudge and probably has long term financial viability issues at this point and lots of rumours that the Saudi's are tied of Saudi Sportswashing Machine, the limitations and would likely move on if given chance.
- Middle East money into Sportswashing is probably dead at this stage (they have bigger problems)
- Private Equity/American investment is a disaster, the bankruptcy rate on firms bought by PE is something like10X the average, they only know how to pay execs and asset strip, not how to make anything successful, financially or product wise (see enbrickification)
Our best hope is the owners eat some humble pie (Levy wasn't that easy to replace), be ruthless with the failures (Vinai/Lange/medical team/etc) and understand that success requires constant investment, and while commercial revenue will offset large parts of that, some years you just have to go to your pockets.